#include <bits/stdc++.h>
using namespace std;
int main() {
  bool k[10001];
  int m, h;
  cin >> m;
  for (int i = 1; i <= m; i++) {
    cin >> h;
    k[h] = true;
  }
  for (int j = 1; j <= m + 1; j++)
    if (k[j] == false) {
      cout << j;
      break;
    }
  return 0;
}
