#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    vector<int> vec;
    int n, v;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> v;
        if (v > 0) vec.push_back(v);
    }
    sort(vec.begin(), vec.end());
    int ans;
    if (vec.empty()) ans = 1;
    else {
        ans = vec[0] - 1 == 0 ? -1 : 1;
        for (int i = 0; i < vec.size() - 1; i++) {
            if (vec[i + 1] - vec[i] >= 2) {
                ans = vec[i] + 1;
                break;
            }
        }
        if (ans == -1) ans = vec[vec.size() - 1] + 1;
    }
    cout << ans << endl;
    return 0;
}