#include <bits/stdc++.h>
using namespace std;
#define FOR(i, n) for(int i = 0; i < (n); i++)
#define MEM(a, x) memset(a, x, sizeof(a))
#define ALL(a) a.begin(), a.end()
#define UNIQUE(a) a.erase(unique(ALL(a)), a.end())
typedef long long ll;

int n;
string s;

int main(int argc, char const *argv[]) {
	ios_base::sync_with_stdio(false);
	cin >> n >> s;
	int cnt = 0;
	FOR(i, n) {
		if (s[i] == 'x') {
			cnt++;
			if (cnt == 2) {
				cout << i << endl;
				return 0;
			}
		}
		else cnt = 0;
	}
	cout << n << endl;
	return 0;
}