#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define REP(i, n) rep(i, 0, n)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define int long long
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
using namespace std;
typedef pair<int, int> P;
const int mod = 1000000007;
const int INF = 1e12;

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n; string s;
    cin >> n >> s;
    int now = 0, ans = s.size();
    rep(i, 0, s.size()){
        if(s[i] == 'x'){
            now++;
            if(now == 2){
                ans = i;
                break;
            }
        }else{
            now = 0;
        }
    }
    cout << ans << endl;
}