#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef struct {
    int x, y, distance;
    bool break_block;
} Node;

int main() {
    int N, M;
    scanf("%d %d", &N, &M);

    int** map = (int**)malloc(sizeof(int*)*N);
    bool*** visited = (bool***)malloc(sizeof(bool**)*N);
    for(int i=0; i<N; i++) {
        map[i] = (int*)malloc(sizeof(int)*M);
        visited[i] = (bool**)malloc(sizeof(bool*)*M);

        char line[M+2];
        scanf("%s",line);

        for(int j=0; j<M; j++) {
            map[i][j] = line[j] - '0';
            visited[i][j] = (bool*)calloc(2, sizeof(bool));
        }
    }

    Node* qu = (Node*)malloc(sizeof(Node)*(N*M*2));
    int front = 0, rear = 0;
    Node start = {0, 0, 1, false};
    visited[0][0][0] = true;
    qu[rear++] = start;

    int dx[4] = {-1,1,0,0};
    int dy[4] = {0,0,1,-1};
    int result = -1;

    while(front != rear) {
        Node now = qu[front++];
        int cx = now.x, cy = now.y, cd = now.distance;
        bool isBreakBlock = now.break_block;

        if(cx==M-1 && cy==N-1) {
            result = cd;
            break;
        }

        for(int i=0; i<4; i++) {
            int nx = cx + dx[i], ny = cy + dy[i], nd = cd + 1;

            if(nx<0 || nx>=M || ny<0 || ny>=N) continue;

            bool isWall = map[ny][nx] == 1;

            if(isWall && isBreakBlock) continue;

            bool next_block_state = isWall || isBreakBlock; // (isWall && !isBreakBlock) || isBreakBlock을 단순화한 값
            int block_state_index = next_block_state ? 1 : 0;

            if(!visited[ny][nx][block_state_index]) {
                Node next = {nx, ny, nd, next_block_state};
                qu[rear++] = next;
                visited[ny][nx][block_state_index] = true;
            }
        }
    }

    printf("%d\n",result);

    for(int i=0; i<N; i++) {
        free(map[i]);
        for(int j=0; j<M; j++) free(visited[i][j]);
        free(visited[i]);
    }

    free(map);
    free(visited);
    free(qu);

    return 0;
}