#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; ++i)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    ll n, ans = 0;
    cin >> n;
    vector<ll> tot(501,0), cnt(501,0);
    rep(i,n){
        int a;
        cin >> a;
        for(ll j=1;j<=500;++j) ans += abs(a-j) * (i * cnt[j] - tot[j]);
        ++cnt[a]; tot[a] += i;
    }
    cout << ans*2 << '\n';
    return 0;
}