diff --git a/Luogu/P1387/P1387.cpp b/Luogu/P1387/P1387.cpp
new file mode 100644
index 00000000..752f3b78
--- /dev/null
+++ b/Luogu/P1387/P1387.cpp
@@ -0,0 +1,38 @@
+#include <bits/stdc++.h>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int n, m, ans;
+bool g[105][105];
+
+bool check(int x1, int y1, int x2, int y2) {
+    for (int i = x1; i <= x2; i++) {
+        for (int j = y1; j <= y2; j++) {
+            if (!g[i][j]) return false;
+        }
+    }
+    return true;
+}
+
+int main() {
+    cin >> n >> m;
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= m; j++) {
+            cin >> g[i][j];
+        }
+    }
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= m; j++) {
+            for (int k = 1; k <= std::min(n, m); k++) {
+                if (i + k > n || j + k > m) break;
+                if (check(i, j, i + k - 1, j + k - 1)) {
+                    ans = std::max(ans, k);
+                }
+            }
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}