diff --git a/problems/terry/p_1.java b/problems/terry/p_1.java
new file mode 100644
index 0000000..fdbaa67
--- /dev/null
+++ b/problems/terry/p_1.java
@@ -0,0 +1,39 @@
+package study.problems;
+
+import java.util.*;
+import java.io.*;
+
+public class p_1 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        //given
+        int n = Integer.parseInt(br.readLine());
+        int[][] arr = new int[n][n];
+
+
+        //when
+        // 배열 초기화
+        for (int i = 0; i < n; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < n; j++) {
+                arr[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        //then
+        int sum = 0;
+
+        for (int i = 0; i < n; i++) {
+            sum += arr[i][i]; // '\' 대각선 요소 합
+            if (i != (n - 1 - i)) // 겹치는 요소 제외
+                sum += arr[i][n - 1 - i]; // '/' 대각선 요소 합
+        }
+
+        bw.write(String.valueOf(sum));
+
+        br.close();
+        bw.close();
+    }
+}
diff --git a/problems/terry/p_2.java b/problems/terry/p_2.java
new file mode 100644
index 0000000..75a563f
--- /dev/null
+++ b/problems/terry/p_2.java
@@ -0,0 +1,43 @@
+package study.problems;
+
+import java.util.*;
+import java.io.*;
+
+
+public class p_2 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+
+        //given
+        int n, m;
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        n = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+        int[][] arr = new int[n][m];
+
+        //when
+        // 배열 초기화
+        for (int i = 0; i < n; i++) {
+            st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < m; j++) {
+                arr[i][j] = Integer.parseInt(st.nextToken()); // 배열 초기화
+            }
+        }
+
+        //then
+        int sum = 0;
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < m; j++) {
+                if (i == 0 || i == (n - 1) || j == 0 || j == (m - 1)) // i 혹은 j가 첫번째, 마지막 인덱스면 더함
+                    sum += arr[i][j];
+            }
+        }
+
+        bw.write(String.valueOf(sum));
+
+        br.close();
+        bw.close();
+    }
+}
diff --git a/problems/terry/p_3.java b/problems/terry/p_3.java
new file mode 100644
index 0000000..448f28a
--- /dev/null
+++ b/problems/terry/p_3.java
@@ -0,0 +1,46 @@
+package study.problems;
+
+import java.util.*;
+import java.io.*;
+
+public class p_3 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        //given
+        int n, m;
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        n = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+        int[][] arr = new int[n][m];
+
+        //when
+        //배열 초기화
+        for (int i = 0; i < n; i++) {
+            st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < m; j++) {
+                arr[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        int[][] reverse = new int[m][n]; // 회전 배열
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < m; j++) {
+                reverse[j][n - 1 - i] = arr[i][j]; // 90도 회전
+            }
+        }
+
+        //then
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                bw.write(reverse[i][j] + " ");
+            }
+            bw.newLine();
+        }
+
+        br.close();
+        bw.close();
+    }
+}
+