#include <iostream>
#include <cstring>
#define nmax 105
using namespace std;

int n, m, dp[nmax][nmax];
string a[nmax];

int main() {
    cin>>n>>m;
    cin.get();
    for(int i=0; i<n; i++) getline(cin, a[i]);


    for(int i=n-1; i>=0; i--)
        for(int j=m-1; j>=0; j--) {
            dp[i][j] = a[i][j] == '&'? 0 : max(dp[i+1][j], dp[i][j+1])+1;
        }
    cout<<dp[0][0]<<"\n";

    return 0;
}