//Given N integers, you are supposed to find the smallest positive integer that is NOT in the given list.
//给定 N 个整数，请你找出最小的不在给定整数列表中的正整数。
#include<iostream>
#include<algorithm>
#include<cstring>
#include<unordered_set>

using namespace std;
int n;
unordered_set<int> S;

int main()
{
    cin>>n;
    while(n--)
    {
        int x;
        cin>>x;
        S.insert(x);
    }
    for(int i = 1; i<100010; i++)
        if(!S.count(i))
        {
            cout<<i;
            break;
        }
    return 0;
}