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 <bits/stdc++.h>
#define N 100010
#define int long long
using namespace std;

signed main(){
  set<int> S;
  int n;
  cin>>n;
  int A[N];
  for(int i=0;i<n;i++) cin>>A[i],S.insert(A[i]);
  sort(A,A+n);

  int ans = 0;
  for(int i=0;i<n;i++){
    if(ans+1 < A[i]) break;
    //    if(!S.count(ans+1)) break;
    ans += A[i];
  }
  cout<<ans+1<<endl;

  return 0;
}