using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = NList;
        if (n > 100) return;
        var ans = 0;
        for (var i = 0; i < n; ++i) for (var j = 0; j < n; ++j) ans += Math.Abs(i - j) * Math.Abs(a[i] - a[j]);
        WriteLine(ans);
    }
}