diff --git "a/LiiNi-coder/202507/21 BOJ \353\204\264\353\252\250\353\204\264\353\252\250 (Easy).md" "b/LiiNi-coder/202507/21 BOJ \353\204\264\353\252\250\353\204\264\353\252\250 (Easy).md"
new file mode 100644
index 00000000..717911af
--- /dev/null
+++ "b/LiiNi-coder/202507/21 BOJ \353\204\264\353\252\250\353\204\264\353\252\250 (Easy).md"	
@@ -0,0 +1,63 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+//TIP 코드를 <b>실행</b>하려면 <shortcut actionId="Run"/>을(를) 누르거나
+// 에디터 여백에 있는 <icon src="AllIcons.Actions.Execute"/> 아이콘을 클릭하세요.
+public class Main {
+    private static BufferedReader br;
+    private static int answer;
+    private static int[][] map;
+    private static int m;
+    private static int n;
+
+    public static void main(String[] args) throws IOException {
+        br = new BufferedReader(new InputStreamReader(System.in));
+        var temp = br.readLine().split(" ");
+        n = Integer.parseInt(temp[0]);
+        m = Integer.parseInt(temp[1]);
+        map = new int[n][m];
+        answer = 0;
+        dfs(0);
+        System.out.println(answer);
+        br.close();
+    }
+
+    private static void dfs(int idx) {
+        //종료
+        if(idx == n*m){
+            answer++;
+            return;
+        }
+        //idx에 네모 없는 것으로 진행
+        int r = idx / m;
+        int c = idx % m;
+        map[r][c] = 0;
+        dfs(idx+1);
+
+        if(isValid(idx)){
+            map[r][c] = 1;
+            dfs(idx+1);
+        }
+    }
+
+    private static boolean isValid(int idx) {
+        int r = idx/m;
+        int c = idx% m;
+        boolean isFirstCol = c == 0;
+        if(isFirstCol) return true;
+        if(r == 0){
+            return true;
+        }
+        boolean leftDown = (map[r][c-1] == 1);
+        boolean leftUp = (map[r-1][c-1] == 1);
+        boolean rightUp = (map[r-1][c] == 1);
+        if(leftDown && leftUp && rightUp){
+            return false;
+        }else{
+            return true;
+        }
+    }
+}
+```