diff --git "a/03do-new30/202502/17 BOJ G3 \353\264\204\353\262\204\353\247\250 2.md" "b/03do-new30/202502/17 BOJ G3 \353\264\204\353\262\204\353\247\250 2.md"
new file mode 100644
index 00000000..b65bc5cf
--- /dev/null
+++ "b/03do-new30/202502/17 BOJ G3 \353\264\204\353\262\204\353\247\250 2.md"	
@@ -0,0 +1,131 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    private static int[] dr = {0, 0, -1, 1};
+    private static int[] dc = {-1, 1, 0, 0};
+    private static int R;
+    private static int C;
+    private static char[][] arr;
+
+    private static class Point {
+        int r;
+        int c;
+        public Point(int r, int c) {
+            this.r = r;
+            this.c = c;
+        }
+    }
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        R = Integer.parseInt(st.nextToken());
+        C = Integer.parseInt(st.nextToken());
+        int N = Integer.parseInt(st.nextToken());
+
+        arr = new char[R][C];
+        for (int i = 0; i < R; i++) {
+            arr[i] = br.readLine().toCharArray();
+        }
+
+        // 3초에 터지는 지점들 저장
+        List<Point> bombAt3Sec = new ArrayList<>();
+        // 5초에 터지는 지점들 저장
+        List<Point> bombAt5Sec = new ArrayList<>();
+        boolean[][] visited = new boolean[R][C];
+        for (int r = 0; r < R; r++) {
+            for (int c = 0; c < C; c++) {
+                if (arr[r][c] == 'O') {
+                    visited[r][c] = true;
+                    bombAt3Sec.add(new Point(r, c));
+                    for (int i = 0; i < 4; i++) {
+                        int nr = r + dr[i];
+                        int nc = c + dc[i];
+                        if (0 <= nr && nr < R && 0 <= nc && nc < C) {
+                            if (arr[nr][nc] == '.' && !visited[nr][nc]) {
+                                visited[nr][nc] = true;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        for (int r = 0; r < R; r++) {
+            for (int c = 0; c < C; c++) {
+                if (!visited[r][c]) {
+                    bombAt5Sec.add(new Point(r, c));
+                }
+            }
+        }
+        
+        // N에 맞게 출력
+        if (N == 1) {
+            for (int r = 0; r < R; r++) {
+                for (int c = 0; c < C; c++) {
+                    bw.write(arr[r][c]);
+                }
+                bw.write("\n");
+            }
+        } else {
+            if (N % 2 == 0) {
+                char[][] filledArr = getFilledArr();
+                for (int r = 0; r < R; r++) {
+                    for (int c = 0; c < C; c++) {
+                        bw.write(filledArr[r][c]);
+                    }
+                    bw.write("\n");
+                }
+            } else {
+                char[][] result;
+                if (N % 4 == 3) {
+                    result = getArr(bombAt3Sec);
+
+                }
+                else{ // N % 4 == 1
+                    result = getArr(bombAt5Sec);
+                }
+                for (int r = 0; r < R; r++) {
+                    for (int c = 0; c < C; c++) {
+                        bw.write(result[r][c]);
+                    }
+                    bw.write("\n");
+                }
+            }
+        }
+
+
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static char[][] getFilledArr() {
+        char[][] ret = new char[R][C];
+        for (int r = 0; r < R; r++) {
+            Arrays.fill(ret[r], 'O');
+        }
+        return ret;
+    }
+
+    private static char[][] getArr(List<Point> points) {
+        char[][] ret = getFilledArr();
+        for (int i = 0; i < points.size(); i++) {
+            Point p = points.get(i);
+            ret[p.r][p.c] = '.';
+            for (int idx = 0; idx < 4; idx ++) {
+                int nr = p.r + dr[idx];
+                int nc = p.c + dc[idx];
+                if (0 <= nr && nr < R && 0 <= nc && nc < C) {
+                    if (ret[nr][nc] == '.') { continue; }
+                    ret[nr][nc] = '.';
+                }
+            }
+        }
+        return ret;
+    }
+}
+```