#include<stdio.h>

int b[101][101], n, m, maxim, coada[20000][2], p, u;
char a[101][101];

int main() {
    int j, x, y;
    scanf("%d", &n);
    scanf("%d", &m);
    for(j = 0; j < n; ++j) {
        scanf("%s", a[j]);
    }
    if(a[0][0] == '&') {
        printf("0");
        return 0;
    }
    coada[0][0] = 0;
    coada[0][1] = 0;
    p = u = 0;
    maxim = 1;
    b[0][0] = 1;
    while(p <= u) {
        x = coada[p][0] + 1;
        y = coada[p][1];
        if(x < n && y < m && a[x][y] == '.' && b[x][y] == 0) {
            coada[++u][0] = x;
            coada[u][1] = y;
            b[x][y] = b[coada[p][0]][coada[p][1]] + 1;
            if(b[x][y] > maxim) maxim = b[x][y];
        }
        x = coada[p][0];
        y = coada[p][1] + 1;
        if(x < n && y < m && a[x][y] == '.' && b[x][y] == 0) {
            coada[++u][0] = x;
            coada[u][1] = y;
            b[x][y] = b[coada[p][0]][coada[p][1]] + 1;
            if(b[x][y] > maxim) maxim = b[x][y];
        }
        ++p;
    }
    printf("%d", maxim);
    return 0;
}