#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  bool flag[3003] = {false};
  int n;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    int temp;
    cin >> temp;
    flag[temp] = true;
  }
  for (int i = 1; i <= n + 1; ++i) {
    if (!flag[i]) {
      cout << i << "\n";
      return 0;
    }
  }
  return 0;
}
