diff --git a/flydongwoo/AlgoLeadMe_Week19_prob01.cpp b/flydongwoo/AlgoLeadMe_Week19_prob01.cpp
new file mode 100644
index 0000000..1a57767
--- /dev/null
+++ b/flydongwoo/AlgoLeadMe_Week19_prob01.cpp
@@ -0,0 +1,35 @@
+#include <iostream>   
+#include <vector>     
+#include <algorithm>  
+
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int N, K;
+    cin >> N >> K;
+    vector<int> a(N);
+
+    for (int i = 0; i < N; i++) {
+        cin >> a[i];
+    }
+
+    long long window_sum = 0;
+
+    for (int i = 0; i < K; i++) {
+        window_sum += a[i];
+    }
+
+    long long max_sum = window_sum;
+
+    for (int i = K; i < N; i++) {
+        window_sum += a[i];
+        window_sum -= a[i - K];
+        max_sum = max(max_sum, window_sum);
+    }
+
+    cout << max_sum << endl;
+    return 0;
+}
diff --git a/flydongwoo/README.md b/flydongwoo/README.md
index 77382e0..da77089 100644
--- a/flydongwoo/README.md
+++ b/flydongwoo/README.md
@@ -19,4 +19,6 @@
 | 15차시 | 2025.07.27 |  DP  | [1, 2, 3 더하기](https://www.acmicpc.net/problem/9095)|https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/55|
 | 16차시 | 2025.08.03 |  구현  | [자리배정](https://www.acmicpc.net/problem/10157)|https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/60|
 | 17차시 | 2025.08.06 |  DFS와 BFS  | [바이러스](https://www.acmicpc.net/problem/2606)|https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/63|
-| 18차시 | 2025.08.07 |  BFS  | [숨바꼭질](https://www.acmicpc.net/problem/1697)|https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/64|
\ No newline at end of file
+| 18차시 | 2025.08.07 |  BFS  | [숨바꼭질](https://www.acmicpc.net/problem/1697)|https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/64|
+| 19차시 | 2025.08.14 |  Sliding Window  | [수열](https://www.acmicpc.net/problem/2559)|https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/71|
+