#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
#ifdef LOCAL
	std::ifstream in("in");
	std::cin.rdbuf(in.rdbuf());
#endif

	int N;
	string s;
	cin >> N >> s;

	int pos = s.find("xx");
	if(pos == string::npos){
		cout << N << endl;
	}
	else{
		cout << pos + 1 << endl;
	}
}