#include <iostream>
#include <math.h>
using namespace std;
int maxx = 1;
int X,Y;
int mapp[100][100];
void upd_res(int a){
    if(a > maxx){
        maxx = a;
    }
}
void find_way(int xw, int yw, int mv){
    if(xw + 1 < X){
        if(mapp[xw+1][yw] == 0){
            find_way(xw+1, yw, mv+1);
        }
    }
    if(yw + 1 < Y){
        if(mapp[xw][yw+1] == 0){
            find_way(xw, yw+1, mv+1);
        }
    }
    upd_res(mv);
}
int main(){
    cin >> X >> Y;
    char n[101] = "&";
    for(int i = 0; i < Y; ++i){
        cin >> n;
        for(int h = 0; h < X; ++h){
            if(n[h] == 38){
                mapp[h][i] = 1;
            }else{
                mapp[h][i] = 0;
            }
        }

    }

    if(mapp[0][0] == 0){
    find_way(0,0,1);
    cout << maxx;
    }else{
    cout << 0;
    }
}