diff --git a/Basic_Of_Algorithm/src/Today22_05_11/bfs.java b/Basic_Of_Algorithm/src/Today_22_05_11/bfs.java
similarity index 98%
rename from Basic_Of_Algorithm/src/Today22_05_11/bfs.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/bfs.java
index 1d7af4b..117d37f 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/bfs.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/bfs.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 import java.util.LinkedList;
 import java.util.Queue;
diff --git a/Basic_Of_Algorithm/src/Today22_05_11/bfsAgain.java b/Basic_Of_Algorithm/src/Today_22_05_11/bfsAgain.java
similarity index 98%
rename from Basic_Of_Algorithm/src/Today22_05_11/bfsAgain.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/bfsAgain.java
index 0a1800b..bca547d 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/bfsAgain.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/bfsAgain.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 import java.util.LinkedList;
 import java.util.Queue;
diff --git a/Basic_Of_Algorithm/src/Today22_05_11/combi_dfs.java b/Basic_Of_Algorithm/src/Today_22_05_11/combi_dfs.java
similarity index 97%
rename from Basic_Of_Algorithm/src/Today22_05_11/combi_dfs.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/combi_dfs.java
index 693874f..4d9802b 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/combi_dfs.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/combi_dfs.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 public class combi_dfs {
 
diff --git a/Basic_Of_Algorithm/src/Today22_05_11/dfs.java b/Basic_Of_Algorithm/src/Today_22_05_11/dfs.java
similarity index 97%
rename from Basic_Of_Algorithm/src/Today22_05_11/dfs.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/dfs.java
index 3190a0d..f468513 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/dfs.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/dfs.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 public class dfs {
 	
diff --git a/Basic_Of_Algorithm/src/Today22_05_11/test.java b/Basic_Of_Algorithm/src/Today_22_05_11/test.java
similarity index 98%
rename from Basic_Of_Algorithm/src/Today22_05_11/test.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/test.java
index d86f3b7..82b89ad 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/test.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/test.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 import java.util.*;
 
diff --git a/Basic_Of_Algorithm/src/Today22_05_11/twoPointer.java b/Basic_Of_Algorithm/src/Today_22_05_11/twoPointer.java
similarity index 98%
rename from Basic_Of_Algorithm/src/Today22_05_11/twoPointer.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/twoPointer.java
index 202e7d6..9fc63d5 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/twoPointer.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/twoPointer.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 import java.util.Arrays;
 
diff --git a/Basic_Of_Algorithm/src/Today22_05_11/twoPointerRangeSum.java b/Basic_Of_Algorithm/src/Today_22_05_11/twoPointerRangeSum.java
similarity index 96%
rename from Basic_Of_Algorithm/src/Today22_05_11/twoPointerRangeSum.java
rename to Basic_Of_Algorithm/src/Today_22_05_11/twoPointerRangeSum.java
index e515221..802aa0a 100644
--- a/Basic_Of_Algorithm/src/Today22_05_11/twoPointerRangeSum.java
+++ b/Basic_Of_Algorithm/src/Today_22_05_11/twoPointerRangeSum.java
@@ -1,4 +1,4 @@
-package Today22_05_11;
+package Today_22_05_11;
 
 import java.util.Arrays;
 
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/RankingSearch.java b/Basic_Of_Algorithm/src/Today_22_05_12/RankingSearch.java
new file mode 100644
index 0000000..df087e1
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/RankingSearch.java
@@ -0,0 +1,86 @@
+package Today_22_05_12;
+
+import java.util.HashMap;
+import java.util.ArrayList;
+import java.util.Collections;
+
+public class RankingSearch {
+
+	static HashMap<String,ArrayList<Integer>> map = new HashMap<>();
+	
+	
+	public static void main(String[] args) {
+		
+		
+		String [] info = {"java backend junior pizza 150","python frontend senior chicken 210","python frontend senior chicken 150","cpp backend senior pizza 260","java backend junior chicken 80","python backend senior chicken 50"};
+		
+		String [] query = {"java and backend and junior and pizza 100","python and frontend and senior and chicken 200","cpp and - and senior and pizza 250","- and backend and senior and - 150","- and - and - and chicken 100","- and - and - and - 150"};
+		
+		int[]result = new int[query.length];
+		
+		
+		for(int i=0;i<info.length;i++) {
+		
+			String[]temp = info[i].split(" ");
+			dfs(temp,0,"");
+			
+		}
+		for(String key : map.keySet()) {
+			Collections.sort(map.get(key));
+		}
+		
+		for(int i=0;i<query.length;i++) {
+			
+			query[i] = query[i].replaceAll(" and ", "");
+			
+			String [] temp = query[i].split(" ");
+			
+			result[i] = map.containsKey(temp[0]) ? binarySearch(temp[0],temp[1]) : 0;  
+		}
+		
+		for(int i : result)System.out.println(i);
+		
+	}
+	
+	static int binarySearch(String key,String value) {
+		
+		int score = Integer.parseInt(value);
+		
+		ArrayList<Integer> list = map.get(key);
+		
+		int start = 0;
+		
+		int end = list.size()-1;
+		
+		
+		while(start<=end) {
+			
+			int mid = (start+end)/2;
+			
+			if(score<=list.get(mid)) end = mid-1;
+			else if(score>list.get(mid)) start = mid+1;
+			
+			
+		}
+		
+		return list.size()-start;
+		
+		
+	}
+	
+	static void dfs(String[]temp,int count,String now) {
+		
+		
+		if(count==4) {
+			if(!map.containsKey(now)) {
+				map.put(now, new ArrayList<>());
+			}
+			map.get(now).add(Integer.parseInt(temp[4]));
+			return;
+		}
+		
+		dfs(temp,count+1,now+"-");
+		dfs(temp,count+1,now+temp[count]);
+		
+	}
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/apchuck.java b/Basic_Of_Algorithm/src/Today_22_05_12/apchuck.java
new file mode 100644
index 0000000..7e9a852
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/apchuck.java
@@ -0,0 +1,57 @@
+package Today_22_05_12;
+
+public class apchuck {
+
+	public static void main(String[] args) {
+		
+		String s = "ababcdcdababcdcd";
+		
+		
+		int answer = Integer.MAX_VALUE;
+		
+		
+		for(int i=1;i<=s.length()/2;i++) {
+			
+			
+			String result = "";
+			String now = ""; String next = "";
+			int count = 1;
+			
+			for(int j=0;j<=s.length()/i;j++) {
+				
+				
+				int start = j*i;
+				
+				int end = s.length() > i * (j+1) ? i * (j+1) : s.length();
+				
+				now = next;
+				
+				next = s.substring(start,end);
+				
+				if(now.equals(next)) {
+					count++;
+				}else {
+					result += check(count) + now;	
+					count = 1;
+				}
+				
+				
+				
+			}
+			
+			result += check(count) + next;
+			
+			System.out.println(result + " -> 갯수 : "+ result.length());
+			
+			answer = Math.min(answer, result.length());
+			
+		}
+		System.out.println();
+		System.out.println("답 : " + answer);
+		
+	}
+	
+	static String check(int count) {
+		return count > 1 ? String.valueOf(count) : ""; 
+	}
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/changebracket.java b/Basic_Of_Algorithm/src/Today_22_05_12/changebracket.java
new file mode 100644
index 0000000..ba24c08
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/changebracket.java
@@ -0,0 +1,68 @@
+package Today_22_05_12;
+
+public class changebracket {
+
+	
+	public static void main(String[] args) {
+		
+		String p = ")(";
+		
+		if(p.isEmpty())System.out.println("nope");
+		else {
+			
+			String answer = change(p);
+			System.out.println(answer);
+		}
+	
+		
+		
+	}
+	
+	static String change(String w) {
+		
+		if(w.isEmpty()) return "";
+		
+		String u = "";
+		String v = "";
+		
+		int l = 0;
+		int r = 0;
+		int i;
+		
+		for(i=0;i<w.length();i++) {
+			
+			char ch = w.charAt(i);
+			
+			if(ch=='(')l++;
+			else r++;
+			
+			
+			if(l==r) break;
+			
+		}
+		
+		u = w.substring(0,i+1);
+		v = w.substring(i+1);
+		
+		if(isRight(u)) {
+			u += change(v);
+		}else {
+			String str = "(" + change(v) + ")";
+			u = u.substring(1,u.length()-1);
+			u = u.replaceAll("\\(", ".");
+			u = u.replaceAll("\\)", "(");
+			u = u.replaceAll("\\.", ")");
+			str += u;
+			return str;
+		}
+		return u;
+		
+	}
+	static boolean isRight(String u) {
+		
+		if(u.charAt(0)==')') return false;
+		u = u.replaceAll("\\(\\)", "");
+		
+		return true;
+	}
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/fef.java b/Basic_Of_Algorithm/src/Today_22_05_12/fef.java
new file mode 100644
index 0000000..84cd39f
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/fef.java
@@ -0,0 +1,51 @@
+package Today_22_05_12;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Stack;
+
+public class fef {
+
+	public static void main(String[] args) {
+		
+		
+		int[][] rooms = {{1,4},{3,5},{0,6},{5,7},{3,8},
+				{5,9},{6,10},{8,11},{8,12},{2,13},
+				{12,14},{11,14}};
+	
+	int answer = 0;
+	
+	Arrays.sort(rooms,new Comparator<int[]>() {
+
+		@Override
+		public int compare(int[] o1, int[] o2) {
+			
+			if(o1[1]==o2[1]) {
+				return o1[0] - o2[0];
+			}
+			return o1[1]-o2[1];
+		}
+		
+	});
+	
+	for(int i=0;i<rooms.length;i++) {
+		System.out.println(rooms[i][0]+" : " + rooms[i][1]);
+	}
+	
+	int end_time = 0;
+	int count = 0;
+	
+	for(int i=0;i<rooms.length;i++) {
+		
+		if(rooms[i][0]>=end_time) {
+			end_time = rooms[i][1];
+			count++;
+		}
+		
+		
+	}
+	
+	System.out.println("답 : " + count);
+	
+	}
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/gameMap.java b/Basic_Of_Algorithm/src/Today_22_05_12/gameMap.java
new file mode 100644
index 0000000..97469a7
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/gameMap.java
@@ -0,0 +1,52 @@
+package Today_22_05_12;
+
+import java.util.*;
+
+public class gameMap {
+
+	public static void main(String[] args) {
+		
+		int[][]maps = {{1,0,1,1,1},{1,0,1,0,1},{1,0,1,1,1},{1,1,1,0,1},{0,0,0,0,1}};
+		
+		int answer = 0;
+		
+		Queue<int[]> q = new LinkedList<>();
+		
+		
+		int[][]temp = new int[maps.length][maps[0].length];
+		
+		int [][] move = {{0,1},{1,0},{0,-1},{-1,0}};
+		
+		
+		temp[0][0] = 1;
+		
+		q.add(new int[] {0,0});
+		
+		while(!q.isEmpty()) {
+			
+			int[]cur = q.poll();
+			
+			int i = cur[0];
+			int j = cur[1];
+			
+			for(int d=0;d<4;d++) {
+				
+				int ni = i + move[d][0]; 
+				int nj = j + move[d][1];
+				
+				if(ni<0||nj<0||maps.length-1<ni||maps[0].length-1<nj) continue;
+				
+				if(maps[ni][nj]==1&&temp[ni][nj]==0) {
+					temp[ni][nj] = temp[i][j] + 1;
+					q.add(new int[] {ni,nj});
+				}
+				
+			}
+			
+		}
+		
+		System.out.println(temp[maps.length-1][maps[0].length-1]);
+		
+		
+	}
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/hide.java b/Basic_Of_Algorithm/src/Today_22_05_12/hide.java
new file mode 100644
index 0000000..02f5737
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/hide.java
@@ -0,0 +1,57 @@
+package Today_22_05_12;
+
+import java.util.*;
+
+public class hide {
+	
+	public static void main(String[] args) {
+		
+		
+		int sb = 5;
+		int bro = 17;
+		
+		
+		
+		Queue<Integer> q = new LinkedList<>();
+		
+		int[] position = new int[100001];
+		
+		
+		position[sb] = 0;
+		
+		q.add(sb);
+		
+		while(!q.isEmpty()) {
+			
+			
+			int p = q.poll();
+			
+			if(position[bro]!=0) break;
+			
+			if(position[p-1] ==0 && p-1>=0) {
+				position[p-1] = position[p] + 1;
+				q.add(p-1);
+			}
+			
+			if(position[p+1] ==0 && p+1<=position.length) {
+				position[p+1] = position[p] + 1;
+				q.add(p+1);
+				
+			}	
+			if(position[p*2] ==0 && p*2<=position.length) {
+				position[p*2] = position[p] + 1;
+				q.add(p*2);
+				
+			}	
+			
+			
+		}
+		
+		if(sb==bro) position[bro] = 0;
+		System.out.println(position[bro] + " 초");
+		
+		
+		
+	}
+
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/hideAndFind.java b/Basic_Of_Algorithm/src/Today_22_05_12/hideAndFind.java
new file mode 100644
index 0000000..a8bbb4e
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/hideAndFind.java
@@ -0,0 +1,66 @@
+package Today_22_05_12;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.PriorityQueue;
+
+public class hideAndFind {
+
+	public static void main(String[] args) {
+	
+		int[][]jobs = {{0, 3}, {1, 9}, {2, 6}};
+		
+		int answer = 0;
+		
+		Arrays.sort(jobs, new Comparator<int[]>() {
+
+			@Override
+			public int compare(int[] o1, int[] o2) {
+				if(o1[0]==o2[0]) {
+					return o1[1] - o2[1];
+				}
+				return o1[0] - o2[0];
+			}
+		
+		});
+		
+		
+		for(int i=0;i<jobs.length;i++) {
+			System.out.println(jobs[i][0]+" : "+jobs[i][1]);
+		}
+		
+		PriorityQueue<int[]> q = new PriorityQueue<int[]>(new Comparator<int[]>() {
+
+			@Override
+			public int compare(int[] o1, int[] o2) {
+				// TODO Auto-generated method stub
+				return o1[1]-o2[1];
+			}
+		
+		});
+		
+		q.offer(jobs[0]);
+		int end = jobs[0][0];
+		int sum = 0;
+		int idx = 1;
+		
+		while(!q.isEmpty()) {
+			int [] cur = q.poll();
+			end += cur[1];
+			sum += end - cur[0];
+			System.out.println(sum);
+			
+			while(idx < jobs.length && jobs[idx][0] <= end) {
+				q.offer(jobs[idx++]);
+			}
+			
+			if(idx < jobs.length && q.isEmpty()) {
+				end = jobs[idx][0];
+				q.offer(jobs[idx++]);
+			}
+		}
+		
+		
+		System.out.println(sum/jobs.length);
+	}
+}
\ No newline at end of file
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/rightbiggersoo.java b/Basic_Of_Algorithm/src/Today_22_05_12/rightbiggersoo.java
new file mode 100644
index 0000000..924108d
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/rightbiggersoo.java
@@ -0,0 +1,37 @@
+package Today_22_05_12;
+
+import java.util.*;
+
+public class rightbiggersoo {
+	
+	public static void main(String[] args) {
+		
+		int []A = {3,5,2,7};
+		int[]answer = new int[A.length];
+		
+		Stack<Integer> ans = new Stack<>();
+		Stack<Integer> tmp = new Stack<>();
+		
+		for(int i = A.length-1; i > -1 ; i--) {
+			
+			int num = A[i];
+			
+			while(!tmp.isEmpty() && (num >= tmp.peek())) {
+				tmp.pop();
+			}
+			
+			if(tmp.isEmpty()) {
+				ans.add(-1);
+			}else {
+				ans.add(tmp.peek());
+			}
+			
+			tmp.add(num);
+			
+		}
+		
+		for(int i = 0 ; i < answer.length;i++) System.out.println(ans.pop());
+		
+	}
+
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_12/rooms.java b/Basic_Of_Algorithm/src/Today_22_05_12/rooms.java
new file mode 100644
index 0000000..3801026
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_12/rooms.java
@@ -0,0 +1,46 @@
+package Today_22_05_12;
+
+import java.util.*;
+
+public class rooms {
+
+	static int answer = Integer.MAX_VALUE;
+	
+	public static void main(String[] args) {
+		
+		int[][] rooms = {{1,4},{3,5},{0,6},{5,7},{3,8},
+						{5,9},{6,10},{8,11},{8,12},{2,13},
+						{12,14}};
+		
+		
+		
+		Arrays.sort(rooms, new Comparator<int[]>() {
+			public int compare(int[]o1,int[]o2) {
+				
+				if(o1[1]==o2[1]) {
+					
+					return o1[0] - o2[0];
+				}
+				return o1[1]-o2[1];
+				
+			}
+		});
+		
+		for(int i=0;i<rooms.length;i++) {
+			System.out.print(rooms[i][0]+",");
+			System.out.println(rooms[i][1]);
+		}
+		int count = 0;
+		int end_time = 0;
+		
+		for(int i=0;i<rooms.length;i++) {
+			if(rooms[i][0]>=end_time) {
+				end_time = rooms[i][1];
+				count++;
+				}
+			}
+		
+		System.out.println(count);
+	}
+	
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_13/dictionary.java b/Basic_Of_Algorithm/src/Today_22_05_13/dictionary.java
new file mode 100644
index 0000000..5d3c17a
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_13/dictionary.java
@@ -0,0 +1,53 @@
+package Today_22_05_13;
+
+import java.util.ArrayList;
+
+public class dictionary {
+	
+	public static void main(String[] args) {
+		
+		String msg = "KAKAO";
+		
+		ArrayList<String> dic = new ArrayList<>();
+		ArrayList<Integer> ans = new ArrayList<>();
+		
+		String alp = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+		
+		dic.add("&&");
+		
+		for(int i=0;i<alp.length();i++) dic.add(""+alp.charAt(i));
+		
+		String now = "";
+		
+		int idx = 0;
+		
+		while(idx<=msg.length()) {
+			
+			if(idx==msg.length()) {
+				ans.add(dic.indexOf(now));
+				break;
+			}
+			
+			String next = ""+msg.charAt(idx);
+			String newOne =now+next;
+			
+			if(dic.contains(newOne)) {
+				now = newOne;
+				idx++;
+				continue;
+			}
+			
+			dic.add(newOne);
+			ans.add(dic.indexOf(now));
+			idx++;
+			now = next;
+			
+		}
+		
+			
+		
+		
+		System.out.println(ans);
+	}
+
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_13/hideAndFind.java b/Basic_Of_Algorithm/src/Today_22_05_13/hideAndFind.java
new file mode 100644
index 0000000..84e7aea
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_13/hideAndFind.java
@@ -0,0 +1,48 @@
+package Today_22_05_13;
+
+import java.util.Queue;
+import java.util.LinkedList;
+
+public class hideAndFind {
+	
+	public static void main(String[] args) {
+		
+		int hider = 17;
+		int finder = 5;
+		
+		
+		Queue<Integer> q = new LinkedList<>();
+		
+		int[]check = new int[100001];
+		
+		check[finder] = 0;
+		
+		q.add(finder);
+		
+		while(!q.isEmpty()) {
+			
+			int pos = q.poll();
+			
+			if(check[hider]!=0 || pos>100000) break;
+			
+			if(pos-1 >= 0 && check[pos-1] ==0 ) {
+				check[pos-1] = check[pos] + 1;
+				q.add(pos-1);
+			}
+			if(pos+1 < check.length && check[pos-1] ==0 ) {
+				check[pos+1] = check[pos] + 1;
+				q.add(pos+1);
+			}
+			if(pos*2 >= 0 && check[pos*2] ==0 ) {
+				check[pos*2] = check[pos] + 1;
+				q.add(pos*2);
+			}
+			
+		}
+		
+		
+		System.out.println(check[hider]);
+		
+	}
+
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_13/practice.java b/Basic_Of_Algorithm/src/Today_22_05_13/practice.java
new file mode 100644
index 0000000..e2bcd16
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_13/practice.java
@@ -0,0 +1,47 @@
+package Today_22_05_13;
+
+import java.util.Comparator;
+import java.util.Arrays;
+
+public class practice {
+	
+	public static void main(String[] args) {
+		
+		int[][] rooms = {{1,4},{3,5},{0,6},{5,7},{3,8},
+				{5,9},{6,10},{8,11},{8,12},{2,13},
+				{12,14}};
+		
+		
+		Arrays.sort(rooms,new Comparator<int[]>() {
+
+			@Override
+			public int compare(int[] o1, int[] o2) {
+				// TODO Auto-generated method stub
+				if(o1[1]==o2[1]) {
+					return o1[0]-o2[0];
+				}
+				return o1[1]-o2[1];
+			}
+			
+		});
+		
+		
+		
+		int end_time = 0;
+		int count = 0;
+		
+		
+		for(int i=0;i<rooms.length;i++) {
+			
+			if(rooms[i][0]>=end_time) {
+				end_time = rooms[i][1];
+				count++;
+			}
+			
+		}
+		
+		
+		System.out.println(count);
+	}
+
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_13/right.java b/Basic_Of_Algorithm/src/Today_22_05_13/right.java
new file mode 100644
index 0000000..b826d66
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_13/right.java
@@ -0,0 +1,41 @@
+package Today_22_05_13;
+
+import java.util.Stack;
+
+public class right {
+
+	public static void main(String[] args) {
+		
+		int [] arr = {3,5,1,7};
+		
+		Stack<Integer> temp = new Stack<>();
+		Stack<Integer> ans = new Stack<>();
+		
+		
+		
+		for(int i=arr.length-1;i>-1;i--) {
+			
+			int num = arr[i];
+			
+			while(!temp.isEmpty() && num>=temp.peek()) {
+				temp.pop();
+			}
+			
+			if(temp.isEmpty()) {
+				ans.add(-1);
+			}else {
+				ans.add(temp.peek());
+			}
+			temp.add(num);
+			
+		}
+		
+		int []result = new int[arr.length];
+		
+		for(int i=0;i<result.length;i++) result[i] = ans.pop();
+		
+		
+		for(int i : result)System.out.print(i+" ");
+		
+	}
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_13/soosick.java b/Basic_Of_Algorithm/src/Today_22_05_13/soosick.java
new file mode 100644
index 0000000..c56e0d2
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_13/soosick.java
@@ -0,0 +1,100 @@
+package Today_22_05_13;
+
+import java.util.ArrayList;
+
+public class soosick {
+	
+	static boolean [] visited = new boolean[3];
+	static char[] sick = {'+','-','*'};
+	static long answer = 0;
+	static ArrayList<Character> opArr = new ArrayList<>();
+	static ArrayList<Long> numArr = new ArrayList<>();
+	
+	
+	public static void main(String[] args) {
+		
+		String expression = "100-200*300-500+20";
+		
+		input(expression);
+		
+		dfs(new char[3],0);
+		
+		System.out.println(answer);
+		
+		
+		
+	}
+	
+	static Long change(char ch,long a, long b) {
+		if(ch=='+') return a+b;
+		else if(ch=='-') return a-b;
+		else if(ch=='*') return a*b;
+		else return (long) 0;
+		
+	}
+	
+
+	static void dfs(char[]p,int count) {
+		
+		if(count==3) {
+
+			ArrayList<Long>numList =new ArrayList<>(numArr);
+			ArrayList<Character>opList =new ArrayList<>(opArr);
+			
+			for(int i=0;i<p.length;i++) {
+				for(int j=0;j<opList.size();j++) {
+					if(p[i]==opList.get(j)) {
+						long a = change(opList.get(j),numList.remove(j),numList.remove(j));
+						opList.remove(j);
+						numList.add(j,a);
+						j--;
+					}
+				}
+			}
+
+				answer = Math.max(answer, Math.abs(numList.get(0)));
+				
+				return;
+			
+		}
+		
+			
+		for(int i=0;i<sick.length;i++) {
+			if(!visited[i]) {
+				visited[i] = true;
+				p[count] = sick[i];
+				dfs(p,count+1);
+				visited[i] = false;
+			}
+			
+		}
+		
+		
+	}
+	
+	static void input(String expression) {
+		
+		String num="";
+		
+		for(int i=0;i<expression.length();i++) {
+			
+			char ch = expression.charAt(i);
+			
+			if(ch>='0'&& ch<='9') num += ch;
+			else {
+				numArr.add(Long.parseLong(num));
+				opArr.add(ch);
+				num="";
+			}
+			
+			
+			
+		}
+		
+		numArr.add(Long.parseLong(num));
+		
+		
+	}
+	
+
+}
diff --git a/Basic_Of_Algorithm/src/Today_22_05_13/testCode.java b/Basic_Of_Algorithm/src/Today_22_05_13/testCode.java
new file mode 100644
index 0000000..698046c
--- /dev/null
+++ b/Basic_Of_Algorithm/src/Today_22_05_13/testCode.java
@@ -0,0 +1,25 @@
+package Today_22_05_13;
+
+import java.util.Stack;
+
+public class testCode {
+	
+	public static void main(String[] args) {
+		
+		int n = 43674;
+		int k = 3;
+		int answer = 0;
+		
+		String num = "";
+		
+		while(n>0) {
+			
+			num = n%k + num;
+			n /= k;
+			
+		}
+		
+		System.out.println(num);
+		
+	}
+}