diff --git "a/Seol-JY/202506/21 BOJ G4 \355\224\214\353\241\234\354\235\264\353\223\234.md" "b/Seol-JY/202506/21 BOJ G4 \355\224\214\353\241\234\354\235\264\353\223\234.md"
new file mode 100644
index 00000000..84bd42c5
--- /dev/null
+++ "b/Seol-JY/202506/21 BOJ G4 \355\224\214\353\241\234\354\235\264\353\223\234.md"	
@@ -0,0 +1,62 @@
+```java
+import java.io.*;
+import java.util.StringTokenizer;
+
+public class Main {
+    static final int INF = 987654321;
+    
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        
+        int n = Integer.parseInt(br.readLine());
+        int m = Integer.parseInt(br.readLine());
+        
+        int[][] dist = new int[n + 1][n + 1];
+        
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (i == j) {
+                    dist[i][j] = 0;
+                } else {
+                    dist[i][j] = INF;
+                }
+            }
+        }
+        
+        for (int i = 0; i < m; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            int c = Integer.parseInt(st.nextToken());
+            
+            dist[a][b] = Math.min(dist[a][b], c);
+        }
+        
+        for (int k = 1; k <= n; k++) {
+            for (int i = 1; i <= n; i++) {
+                for (int j = 1; j <= n; j++) {
+                    if (dist[i][k] != INF && dist[k][j] != INF) {
+                        dist[i][j] = Math.min(dist[i][j], dist[i][k] + dist[k][j]);
+                    }
+                }
+            }
+        }
+        
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (dist[i][j] == INF) {
+                    bw.write("0 ");
+                } else {
+                    bw.write(dist[i][j] + " ");
+                }
+            }
+            bw.newLine();
+        }
+        
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+}
+```