#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001



int main(){
	
	int n,m;
	cin>>n>>m;
	vector<string> s(n);
	rep(i,n)cin>>s[i];
	int ans = 0;
	rep(i,m){
		int c = 0;
		rep(j,n){
			if(s[j][i]=='o')c++;
		}
		c = n-c;
		c++;
		ans = max(ans,c);
	}
	cout<<ans<<endl;
	
	return 0;
}