#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define SZ(v) ((int)(v.size()))
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using indexed_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
constexpr int N = 52;
constexpr int mod = 1e9+7;
void run () {
    int n;
    cin >> n;
    vector<ll> a(n);
    map<ll, ll> freq;
    for (ll &i : a) {
        cin >> i;
        freq[i]++;
    }
    ll sum = 0;
    for (auto i : freq) {
        ll num1 = i.first;
        ll num1Freq = i.second;
        for (auto j : freq) {
            ll num2 = j.first;
            ll num2Freq = j.second;
            ll diff = abs(num1 - num2);
            sum += num2Freq * num1Freq * diff * diff * 1ll;
        }
    }
    cout << sum / 2;
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
//    freopen("/home/hamoudi/Coding/run.in", "r", stdin);
    int tt = 1;
//    cin >> tt;
    while (tt--)
        run();
    return 0;
}