```javaimport java.util.*;

public class Main {

static int x, y;
// 图
static int[][] grahp;
// 记录每个点到起点的距离
static int[][] distance;


static class Node {
    int x;
    int y;

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

public static void main(String[] args) {

    Scanner scan = new Scanner(System.in);
    x = scan.nextInt();
    y = scan.nextInt();

    grahp = new int[x][y];
    distance = new int[x][y];

    for (int i = 0; i < x; i++ ){
        for (int j = 0; j < y; j++)  {
            grahp[i][j] = scan.nextInt();
        }
    }


    System.out.println(bfs());

}

static int bfs() {
    int head = 0, tail = 0;

    Queue<Node> queue = new LinkedList();
    queue.offer(new Node(0,0));

    // 向量. 分别代表一个点的上下左右4个端点坐标.

    // 垂直向量. 顺序代表上下左右
    int[] verticalVector = new int[]{0, 1, 0, -1};
    // 水平向量. 顺序代表上下左右
    int[] horizontalVector = new int[]{-1, 0, 1, 0};

    while (!queue.isEmpty()) {
        Node h = queue.poll();

        // 谁先走到就立即退出.
        if (h.x == x - 1 && h.y == y - 1) {
            break;
        }

        for (int i = 0; i < 4; i++) {
            int _x = h.x + verticalVector[i];
            int _y = h.y + horizontalVector[i];

            // 判断是否在边界内
            // 并且该位置可以走, 且没有走过
            if (_x >=0 && _y >=0 && _x < x && _y < y && grahp[_x][_y] == 0 && distance[_x][_y] == 0) {
                distance[_x][_y] = distance[h.x][h.y] + 1;
                queue.offer(new Node(_x, _y));
            }
        }

    }

    return distance[x - 1][y - 1];
}

}
```