#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    ll n;
    cin >> n;
    vector<int> a(n);
    rep(i,n) cin >> a[i];
    ll ans = 0;
    rep(i,n)rep(j,n) ans += abs(i-j)*abs(a[i]-a[j]);
    cout << ans << endl;
    return 0;
}