Problem: The currency system in the Kingdom of Yoax-Musty is strange and fairly inefficient. Like other countries, the kingdom has its own currencty unit denoted by K $ (kingdom dollar). However, the Ministry of Finance issues bills for every value between 1 K $ and (231 - 1) K $ worth.

On the other hand, this system often enables people to make many different values just with a small number of bills. For example, if you have four bills of 1 K $, 2 K $, 4 K $, and 8 K $ worth respectively, you can make any values from 1 K #36; to 15 K $.

In this problem, you are requested to write a program that finds the minimum value that cannot be made with a given set (multiset in a mathematical sense) of bills. For the case with the four bills (1 K $, 2 K $, 4 K $, and 8 K $), since you can make any values up to 15 K $, your program should report 16 K $.



Input

The input consists of two lines. The first line contains an integer N (1 ≤ N ≤ 10000), the number of bills. The second line contains N integers, each of which represents the value of a bill in K $. There may be multiple bills of the same value.

Output

Print the minimum value unable to be made on a line. The value should be given in K $ and without any currency sign or name.

Example

Input




Output

Solution (in CPP):

Solution:
#include <iostream>
#include <string>
#include <map>
#include <vector>
#include <algorithm>
#include <cmath>
#define rep(i, a, b) for(int i = a; i < b; i++)
#define INF 1152921504606846976ll
using namespace std;
typedef long long ll;
int n;

int main(){
	cin >> n;
	vector<ll> a(n+1);
	rep(i, 0, n){
		cin >> a[i];
	}
	a[n] = INF;
	sort(a.begin(), a.end());
	ll s = 1;
	if(a[0] != 1) {
		cout << 1 << endl;
		return 0;
	}
	rep(i, 1, n+1){
		//cout << a[i] << " "<< s << endl;
		if(a[i] > s + 1){
			cout << s + 1 << endl;
			return 0;
		}
		s+=a[i];
	}
	cout << "unko\n";
}