#include <bits/stdc++.h>
using namespace std;
int n, m, a[104][104], visited[104][104];
int dy[] = {1, 0, -1, 0};
int dx[] = {0, 1, 0, -1};
void dfs(int y, int x){
    for(int i = 0; i < 4; i++){
        int ny = y + dy[i];
        int nx = x + dx[i];
        if(ny < 0 || nx < 0 || ny >= n || nx >= m || visited[ny][nx] || !a[ny][nx]) continue;
        visited[ny][nx] = visited[y][x] + 1;
        dfs(ny, nx);
    }
}
 
int main(){
    scanf("%d %d", &n, &m);
    for(int i = 0; i < n; i++){
        for(int j = 0; j < m; j++){
            scanf("%1d", &a[i][j]);
        }
    }
    visited[0][0] = 1;
    dfs(0, 0);
    printf("%d\n", visited[n - 1][m - 1]);
}

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NCA2CjEwMTExMQoxMDEwMTAKMTAxMDExCjExMTAxMQ==

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