diff --git "a/hyeokbini/9658.\353\217\214 \352\262\214\354\236\204 4/9658.cpp" "b/hyeokbini/9658.\353\217\214 \352\262\214\354\236\204 4/9658.cpp"
new file mode 100644
index 0000000..568e2bc
--- /dev/null
+++ "b/hyeokbini/9658.\353\217\214 \352\262\214\354\236\204 4/9658.cpp"	
@@ -0,0 +1,38 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(0);
+    //freopen("test.txt", "rt", stdin);
+    int n;
+    cin >> n;
+    vector<bool> dp(n + 1);
+    dp[1] = false;
+    dp[2] = true;
+    dp[3] = false;
+    dp[4] = true;
+    for(int i = 5; i <= n; i++)
+    {
+        if(!dp[i - 4] || !dp[i - 3] || !dp[i - 1])
+        {
+            dp[i] = true;
+        }
+        else
+        {
+            dp[i] = false;
+        }
+    }
+
+    if(dp[n])
+    {
+        cout << "SK";
+    }
+    else
+    {
+        cout << "CY";
+    }
+    return 0;
+}
diff --git a/hyeokbini/README.md b/hyeokbini/README.md
index 43f1d9f..85ea1bf 100644
--- a/hyeokbini/README.md
+++ b/hyeokbini/README.md
@@ -24,3 +24,4 @@
  | 20차시 | 2025.08.14 |  완전탐색,DFS  | [모음사전](https://school.programmers.co.kr/learn/courses/30/lessons/84512)|[#20](https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/72)|
  | 21차시 | 2025.08.19 |  브루트포스  | [제곱수 찾기](https://www.acmicpc.net/problem/1025)|[#21](https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/76)|
  | 22차시 | 2025.08.22 |  그래프 탐색  | [차량 배치](https://www.acmicpc.net/problem/30206)|[#22](https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/77)|
+ | 25차시 | 2025.09.10 |  DP, 게임 이론  | [돌 게임 4](https://www.acmicpc.net/problem/9658)|[#22](https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/90)|