diff --git "a/ksinji/202510/13 PGM \352\260\200\354\236\245 \353\250\274 \353\205\270\353\223\234.md" "b/ksinji/202510/13 PGM \352\260\200\354\236\245 \353\250\274 \353\205\270\353\223\234.md"
new file mode 100644
index 00000000..71c02561
--- /dev/null
+++ "b/ksinji/202510/13 PGM \352\260\200\354\236\245 \353\250\274 \353\205\270\353\223\234.md"	
@@ -0,0 +1,47 @@
+```java
+import java.util.*;
+
+class Solution {
+    public int solution(int n, int[][] edge) {
+        List<List<Integer>> graph = new ArrayList<>();
+        
+        for (int i = 0; i <= n; i++) {
+            graph.add(new ArrayList<>());
+        }
+        
+        for (int[] e : edge) {
+            graph.get(e[0]).add(e[1]);
+            graph.get(e[1]).add(e[0]);
+        }
+        
+        int[] dist = new int[n+1];
+        Arrays.fill(dist, -1);
+        
+        Queue<Integer> q = new LinkedList<>();
+        q.add(1);
+        dist[1] = 0;
+        
+        while (!q.isEmpty()) {
+            int cur = q.poll();
+            for (int next : graph.get(cur)) {
+                if (dist[next] == -1) {
+                    dist[next] = dist[cur] + 1;
+                    q.add(next);
+                }
+            }
+        }
+        
+        int max = Integer.MIN_VALUE;
+        
+        for (int d : dist) {
+            if (d > max) max = d;
+        }
+        
+        int answer = 0;
+        
+        for (int d : dist) if (d == max) answer++;
+        
+        return answer;
+    }
+}
+```