#include <iostream>
#include <stdio.h>
#include <queue> 
#include <algorithm>  
using namespace std;

int n,m,d[110][110];

int main()
{
//	freopen("f.in","r",stdin);
	int maxim = 0;

	int i = 1, j = 1;
	scanf("%d%d",&n,&m);
	for(i = 1; i <= n; i++){
		 getchar();
		for(j = 1; j <= m; j++){
			char c = getchar();
			if(c == '&')
				d[i][j] = -1;
		}
	}
	++m,++n;
	for(i = 0; i <= m; i++)
		d[0][i] = -1,d[n + 1][i] = -1;
	for(j = 0; j <= n; j++)
		d[j][0] = -1,d[j][m] = -1;

	pair<int,int> start;
	start.first = 1; start.second = 1;

	queue<pair<int,int>> Q;
	pair<int,int> now;
	if(d[1][1] == 0)
		Q.push(start),
		d[1][1] = 1;
	
	while (Q.size()){			
		now = Q.front(); Q.pop(); 
		i = now.first;
		j = now.second;
		if(j < m && i < n){
			if(d[i + 1][j] == 0){
				d[i + 1][j] = d[i][j] + 1;
				Q.push(make_pair(i + 1, j));
			}
			if(d[i][j + 1] == 0){
				d[i][j + 1] = d[i][j] + 1;
				Q.push(make_pair(i, j + 1));
			}
		}
	}


	for(i = 1; i < n; i++)
		for(j = 1; j < m; j++){
			maxim = max(d[i][j],maxim);
		}
		printf("%d\n",maxim);
	return 0;
}
/*
int main(){
//	freopen("f.in","r",stdin);
	scanf("%d%d",&n,&m);
	int i,j;
	char c;
	for(i = 1; i <= n; i++){
		getchar();
		for(j = 1; j <= m; j++){
			c = getchar();
			if(c == '&')
				d[i][j] = -1;
		}
	}
	if(d[1][1] == 0){
		d[1][1] = 1;
		int last = 1;
		for(i = 1; i <= n; i++){
			for(j = 1; j <= m; j++){
				if(d[i][j] == -1 && d[i - 1][j] < 1 && j > last)
					break;
				else{
					d[i][j] = d[i][j] == -1 ? -1 : max(d[i][j - 1],d[i - 1][j]) + 1;
					last = j;
				}
			}
		}
	}
	int maxim = 0;
	for(i = 1; i <= n; i++)
		for(j = 1; j <= m; j++){
			maxim = max(d[i][j],maxim);
		}
		printf("%d\n",maxim);
			
	return 0;
}*/