#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)(s); i < (int)(e); ++i)

int main() {
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	
	int N;
	cin >> N;
	vector<ll> A(N);
	rep(i, 0, N) cin >> A[i];
	
	int maxi = 510;
	vector<ll> cnt(maxi), sum(maxi);
	ll ans = 0;
	rep(i, 0, N) {
		rep(j, 0, maxi) ans += abs(A[i] - j) * (i*cnt[j] - sum[j]);
		++cnt[A[i]];
		sum[A[i]] += i;
	}
	cout << ans*2 << '\n';
}