#include <bits/stdc++.h>
const int A = 3e3 + 10;
int n, a, freq[A];
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a);
    freq[a]++;
  }
  for (int i = 1; i < A; i++) {
    if (!freq[i]) {
      printf("%d\n", i);
      break;
    }
  }
  return 0;
}
