diff --git a/climbing-stairs/Yiseull.py b/climbing-stairs/Yiseull.py
new file mode 100644
index 0000000000..ae3e98cee2
--- /dev/null
+++ b/climbing-stairs/Yiseull.py
@@ -0,0 +1,11 @@
+class Solution:
+    def climbStairs(self, n: int) -> int:
+        if n == 1: return 1
+
+        dp = [0 for _ in range(n + 1)]
+        dp[0], dp[1] = 1, 1
+
+        for i in range(2, n + 1):
+            dp[i] = dp[i - 1] + dp[i - 2]
+
+        return dp[n]
diff --git a/product-of-array-except-self/Yiseull.py b/product-of-array-except-self/Yiseull.py
new file mode 100644
index 0000000000..b30a955c49
--- /dev/null
+++ b/product-of-array-except-self/Yiseull.py
@@ -0,0 +1,15 @@
+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        n = len(nums)
+        answer = [1]
+
+        # answer[i] -> nums[i] 왼쪽 값들의 곱
+        for i in range(1, n):
+            answer.append(answer[i - 1] * nums[i - 1])
+
+        tmp = 1
+        for i in range(n - 1, -1, -1):
+            answer[i] *= tmp
+            tmp *= nums[i]
+
+        return answer
diff --git a/valid-anagram/Yiseull.py b/valid-anagram/Yiseull.py
new file mode 100644
index 0000000000..b755e03fb8
--- /dev/null
+++ b/valid-anagram/Yiseull.py
@@ -0,0 +1,5 @@
+from collections import Counter
+
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        return Counter(s) == Counter(t)