#include<iostream>
#include<deque>
using namespace std;
int n;
int sum;
deque<int> dq;
void beat(int a, int b);
int price;
int main()
{
    freopen("treats.in","r",stdin);
    freopen("treats.out","w",stdout);
    cin >> n;
    for(int i = 0; i < n; ++i)
    {
        int t;
        cin >> t;
        dq.push_back(t);
    }
    while(price < n)
    {
        int x = dq.front();
        int y = dq.back();
        beat(x, y);
    }
    cout << sum << endl;
    return 0;
}
void beat(int a, int b)
{
    price++;
    if(a * price < b * price)
    {
        sum += a * price;
        dq.pop_front();
    }
    else
    {
        sum += b * price;
        dq.pop_back();
    }
}