#include <cmath>
#include <iostream>
using namespace std;

constexpr int U = 510;

long long cnt0[U];
long long cnt1[U];

int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);

    int N;
    cin >> N;

    long long ret = 0;

    for (int i = 0; i < N; ++i) {
        int a;
        cin >> a;
        for (int b = 0; b < U; ++b) {
            ret += abs(a - b) * (cnt0[b] * i - cnt1[b]);
        }
        cnt0[a] += 1;
        cnt1[a] += i;
    }

    cout << ret * 2 << '\n';
}