#include <bits/stdc++.h>
using namespace std;
int w , h , b[1005][85] , ans , sum , next[4][2] = {{1 , 0} , 
                                                    {0 , 1} , 
                                                    {-1 , 0} , 
                                                    {0 , -1}};//也就写了亿遍
char f[1005][85];
void dfs(int x , int y)//基础深搜
{
    for (int i = 0 ; i < 4 ; i++)
    {
        int tx = x + next[i][0] , ty = y + next[i][1];
        if (tx >= 1 && tx <= h && ty >= 1 && ty <= w && f[tx][ty] == '*' && b[tx][ty] == 0)
        {
            b[tx][ty] = 1;
            sum++;
            dfs(tx , ty);
        }
    }
    return;
}

int main()
{
    cin >> w >> h;
    for (int i = 1 ; i <= h ; i++)
    {
        for (int j = 1 ; j <= w ; j++)
        {
            cin >> f[i][j];
        }
    }

    for (int i = 1 ; i <= h ; i++)
    {
        for (int j = 1 ; j <= w ; j++)
        {
            if (b[i][j] == 0 && f[i][j] == '*')
            {
                sum = 1;//注意初始化
                b[i][j] = 1;
                dfs(i , j);
                ans = max(ans , sum);
            }
        }
    }
    cout << ans;
    return 0;
}//已AC