#include <bits/stdc++.h>
using namespace std;
int n, val;
bool used[3005] = {0};
int main() {
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> val;
    used[val] = true;
  }
  for (int i = 1; i <= n + 1; ++i) {
    if (!used[i]) {
      cout << i << endl;
      return 0;
    }
  }
  return 0;
}
