diff --git "a/LiiNi-coder/202512/14 PGM \354\240\204\355\231\224\353\262\210\355\230\270 \353\252\251\353\241\235.md" "b/LiiNi-coder/202512/14 PGM \354\240\204\355\231\224\353\262\210\355\230\270 \353\252\251\353\241\235.md"
new file mode 100644
index 00000000..a2d95471
--- /dev/null
+++ "b/LiiNi-coder/202512/14 PGM \354\240\204\355\231\224\353\262\210\355\230\270 \353\252\251\353\241\235.md"	
@@ -0,0 +1,19 @@
+```java
+import java.util.*;
+
+class Solution {
+    public boolean solution(String[] phone_book) {
+        
+        Arrays.sort(phone_book);
+        for(int i = 0; i < phone_book.length - 1; i++){
+            String now = phone_book[i];
+            String next = phone_book[i + 1];
+            if(next.startsWith(now)){
+                return false;
+            }
+        }
+        return true;
+    }
+}
+
+```