#include<iostream>
#include <stdio.h>
#include <algorithm>
using namespace std;
const int N = 105;
long long a[N],b[N*N];
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF){
        for(int i=1;i<=n;i++){
            scanf("%lld",&a[i]);
        }
        int id = 0;
        for(int i=1;i<=n;i++){
            for(int j=i+1;j<=n;j++){
                b[id++] = a[i]+a[j];
            }
        }
        sort(b,b+id);
        long long sum = b[0];
        for(int i=1;i<id;i++){
            if(b[i]==b[i-1]) continue;
            sum=sum+b[i];
        }
        printf("%lld\n",sum);
    }
    return 0;
}