diff --git a/kangrae-jo/Greedy/11-kangrae-jo.cpp b/kangrae-jo/Greedy/11-kangrae-jo.cpp
new file mode 100644
index 0000000..fabfbc4
--- /dev/null
+++ b/kangrae-jo/Greedy/11-kangrae-jo.cpp
@@ -0,0 +1,28 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int main() {
+    int N;
+    cin >> N;
+
+    vector<int> ATM(N);
+    for (int i = 0; i < N; i++) {
+        cin >> ATM[i];
+    }
+
+    sort(ATM.begin(), ATM.end());
+
+    int result = 0;
+    for (int wait = 0; wait < N; wait++) {
+        for (int use = 0; use <= wait; use++) {
+            result += ATM[use];
+        }
+    }
+
+    cout << result;
+
+    return 0;
+}
\ No newline at end of file
diff --git a/kangrae-jo/README.md b/kangrae-jo/README.md
index d157cfe..00bb584 100644
--- a/kangrae-jo/README.md
+++ b/kangrae-jo/README.md
@@ -11,5 +11,6 @@
 | 7차시 | 2024.11.09 |  DP  | [1로 만들기](https://www.acmicpc.net/problem/1463)|[#12](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/24|)
 | 8차시 | 2024.11.12 |  HEAP  | [더 맵게](https://school.programmers.co.kr/learn/courses/30/lessons/42626)|[#27](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/27|)
 | 9차시 | 2024.11.23 |  DP  | [정수 삼각형](https://school.programmers.co.kr/learn/courses/30/lessons/43105)|[#30](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/30|)
+| 11차시 | 2024.12.21 |  Greedy  | [ATM](https://www.acmicpc.net/problem/11399)|[#41](https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/41|)
 
 ---
\ No newline at end of file