#include<iostream>
#include<cstring>
using namespace std;
int w,h;
char c[505][50005];
int sum[50005];
int maxx;
int main(){
    freopen("snow.in","r",stdin);
    freopen("snow.out","w",stdout);
    cin>>w>>h;//H行W列 
    for(int i=1;i<=h;i++){
        for(int j=1;j<=w;j++){
            cin>>c[i][j];
            if(c[i][j]=='*'){
                int len=h-i;
                int l,r;
                if(j-len>=1){
                    l=j-len;
                }else l=1;
                if(j+len<=w){
                    r=j+len;
                }else r=w;
                for(int k=l;k<=r;k++){
                    sum[k]++;
                }
            }
                
            
        }
    }
    for(int i=1;i<=w;i++){
        maxx=max(sum[i],maxx);
    }
    cout<<maxx<<endl;
    return 0;
}