diff --git a/dohyeondol1/DP/12-dohyeondol1.cpp b/dohyeondol1/DP/12-dohyeondol1.cpp
new file mode 100644
index 0000000..c68d23e
--- /dev/null
+++ b/dohyeondol1/DP/12-dohyeondol1.cpp
@@ -0,0 +1,25 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+int main() {
+    int N, K;
+    cin >> N >> K;
+
+    vector<vector<int>> dp(N+1, vector<int> (K+1, 0));
+    for(int i = 0; i <= N; i++) {
+        dp[i][0] = 1;
+        dp[i][1] = 1;
+    }
+    
+    for(int i = 0; i <= K; i++) 
+        dp[0][i] = 1;
+
+    for(int i = 1; i <= N; i++)
+        for(int j = 2; j <= K; j++)
+            dp[i][j] = (dp[i-1][j] + dp[i][j-1])%1000000000;
+    
+    cout << dp[N][K] << '\n';
+    
+    return 0;
+}
\ No newline at end of file
diff --git a/dohyeondol1/README.md b/dohyeondol1/README.md
index 9ee1aad..be0c735 100644
--- a/dohyeondol1/README.md
+++ b/dohyeondol1/README.md
@@ -13,3 +13,4 @@
  | 9차시 | 2025.04.30 |  그리디 알고리즘  | [체육복](https://school.programmers.co.kr/learn/courses/30/lessons/42862)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/33|
  | 10차시 | 2025.05.04 |  완전 탐색  | [소수 찾기](https://school.programmers.co.kr/learn/courses/30/lessons/42839)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/37|
  | 11차시 | 2025.05.06 |  DP  | [동전 1](https://www.acmicpc.net/problem/2293)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/39|
+ | 12차시 | 2025.05.11 |  DP  | [합분해](https://www.acmicpc.net/problem/2225)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/45|