B. Inna and New Matrix of Candies-Codeforces

B. Inna and New Matrix of Candies-Codeforces

// working.cpp by Bill Weinman <http://bw.org/>
#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n,m;
	cin>>n>>m;
	string s;
	vector<int>s1;
	vector<int>::iterator it;
	for(int i=1;i<=n;i++)
	{
		cin>>s;
		s1.push_back(s.find('S')-s.find('G'));
	}
	sort(s1.begin(),s1.end());
	it=unique(s1.begin(),s1.end());
	s1.resize(distance(s1.begin(),it));
	if(*s1.begin()<0)
		cout<<"-1"<<endl;
	else
		cout<<s1.size()<<endl;

	return 0;
}