#include<iostream>
#include<cmath>
#include<queue>
#include<cstdio>
#include<cstdlib>
#include<cassert>
#include<cstring>
#include<climits>
#include<sstream>
#include<deque>
#include<vector>
#include<algorithm>
#include<set>
#include<map>
#include<bitset>

#define REP(i,s,n) for(int i=s;i<n;i++)
#define rep(i,n) REP(i,0,n)

using namespace std;

typedef long long ll;
const int IINF = INT_MAX;
const ll LLINF = LLONG_MAX;

int main(){
  int n;
  cin >> n;
  string s;
  cin >> s;
  int cnt = 0,i;
  for(i=0;i<n;++i) {
    if( s[i] == 'x' ) {
      ++cnt;
      if( cnt == 2 ) break;
    } else {
      cnt = 0;
    }
  }
  cout << i << endl;
  return 0;
}