diff --git a/NeetCode/combination-sum-2/step1.py b/NeetCode/combination-sum-2/step1.py
new file mode 100644
index 0000000..8ca8c56
--- /dev/null
+++ b/NeetCode/combination-sum-2/step1.py
@@ -0,0 +1,55 @@
+"""
+candidatesに負の値が含まれるのかは重要
+"""
+
+from collections import Counter
+
+class Solution:
+    def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:
+        res = []
+        counts = Counter(candidates)
+        unique_candidates = list(counts.keys())
+        comb = []
+        
+        def append_comb(index, sum_values):
+            if sum_values == target:
+                res.append(comb.copy())
+                return
+            if sum_values > target or index == len(unique_candidates):
+                return
+            
+            append_comb(index + 1, sum_values)
+            num = unique_candidates[index]
+            for i in range(counts[num]):
+                comb.append(num)
+                append_comb(index + 1, sum_values + num * (i + 1))
+            for _ in range(counts[num]):
+                comb.pop()
+        
+        append_comb(0, 0)
+        return res
+
+class Solution:
+    def combinationSum2(self, candidates: List[int], target: int) -> List[List[int]]:
+        res = []
+        sorted_candidates = sorted(candidates)
+        comb = []
+        
+        def append_comb(index, sum_vals):
+            if sum_vals == target:
+                res.append(comb.copy())
+                return
+            if sum_vals > target or index == len(candidates):
+                return
+            
+            num = sorted_candidates[index]
+            comb.append(num)
+            append_comb(index + 1, sum_vals + num)
+            comb.pop()
+            
+            while index + 1 < len(candidates) and sorted_candidates[index] == sorted_candidates[index + 1]:
+                index += 1
+            append_comb(index + 1, sum_vals)
+        
+        append_comb(0, 0)
+        return res
diff --git a/NeetCode/combination-sum-2/step2.py b/NeetCode/combination-sum-2/step2.py
new file mode 100644
index 0000000..78606bf
--- /dev/null
+++ b/NeetCode/combination-sum-2/step2.py
@@ -0,0 +1,3 @@
+"""
+まあtotalのほうが良いか
+"""
diff --git a/NeetCode/subsets-2/step3.py b/NeetCode/subsets-2/step3.py
new file mode 100644
index 0000000..4e3929f
--- /dev/null
+++ b/NeetCode/subsets-2/step3.py
@@ -0,0 +1,7 @@
+aaaa
+ere
+
+fa
+f
+ewq
+af