#include <bits/stdc++.h>
using namespace std;
bool arr[3001];
int main() {
  int a, i, n;
  scanf("%d", &n);
  memset(arr, false, sizeof(bool) * (n + 1));
  for (i = 0; i < n; i++) {
    scanf("%d", &a);
    arr[a] = true;
  }
  i = 1;
  while (arr[i]) i++;
  printf("%d\n", i);
  return 0;
}
