#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  string str;
  while (cin >> n >> str) {
    int ans = 0;
    for (int i = 0; i < (int)str.length(); i++) {
      ans++;
      if (str[i] == '0') {
        break;
      }
    }
    cout << ans << endl;
  }
  return 0;
}
