런타임 에러

package main.java;

import java.util.*;

public class Main {
    static int[][] board;
    static Queue<Point> queue;
    static int[] dx = {-1,-1,0,1,1,1,0,-1};
    static int[] dy = {0,1,1,1,0,-1,-1,-1};
    static int n,count;

    public static void BFS(){
        while(!queue.isEmpty()){
            Point tmp = queue.poll();
            for(int i=0;i<8;i++){
                int nx = tmp.x + dx[i];
                int ny = tmp.y + dy[i];
                if(nx>=0&&nx<n&&ny>=0&&ny<n&&board[nx][ny]==1){
                    board[nx][ny] = 0;
                    queue.offer(new Point(nx,ny));
                }
            }
        }
        count++;
    }




    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        board = new int[n][n];

        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                board[i][j] = sc.nextInt();
            }
        }
        queue = new LinkedList<>();

        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                if(board[i][j]==1){
                    board[i][j] =0;
                    queue.offer(new Point(i,j));
                    BFS();
                }
            }
        }
        System.out.println(count);


    }
}

class Point{
    int x;
    int y;
    public Point(int x, int y){
        this.x = x;
        this.y = y;
    }
}

안녕하세요 이렇게 작성했는데 런타임 에러가 나는데 혹시 어디가 잘못된걸까요?