#include <bits/stdc++.h>
int main() {
  const int maxN = 3002;
  bool tests[maxN] = {0};
  int n(0);
  scanf("%d", &n);
  for (int k = 0; k < n; k++) {
    int temp;
    scanf("%d", &temp);
    tests[temp] = 1;
  }
  for (int index = 1; index < maxN; index++) {
    if (!tests[index]) {
      printf("%d\n", index);
      break;
    }
  }
  return 0;
}
