#include<bits/stdc++.h>
using namespace std;
#define sz(x) (int)(x).size() 
#define int long long int
#define loop(i,a,b) for(int i=a;i<b;i++)
#define scan(arr,n) for (int i = 0; i < n; ++i) cin >> arr[i]
#define vi vector<int>
#define si set<int>
#define pii pair <int, int>
#define sii set<pii>
#define vii vector<pii>
#define mii map <int, int>
#define pb push_back
#define ff first
#define ss second
#define all(aa) aa.begin(), aa.end()
#define rall(a) a.rbegin() , a.rend()
#define read(a,b) int a,b;  cin>>a>>b
#define readt(a,b,c) int a,b,c; cin>>a>>b>>c
#define readf(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d;
#define print(v) for(auto x:v) cout<<x<<" ";cout<<endl
#define printPair(res) for(pair<int,int>& p:res) cout<<p.first<<" "<<p.second<<endl;
#define faster ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)

int fac[300001];
void fact(int m){fac[0]=1;for(int i=1;i<=300000;i++) fac[i]=(fac[i-1]%m * i%m)%m;}
/* Iterative Function to calculate (x^y)%p in O(log y)*/
long long power( long long x,  int y, int p){   long long res = 1;  
x = x % p; while (y > 0) { if (y & 1)  res = (res * x) % p;  y = y >> 1; x = (x * x) % p;} return res;}
// Returns n^(-1) mod p 
long long modInverse( long long n, int p) {  return power(n, p - 2, p); }
long long nCr( long long n,int r, int p) { if (r == 0) return 1; if(n<r) return 0;
return (fac[n] * modInverse(fac[r], p) % p * modInverse(fac[n - r], p) % p) % p; } 

int binarySearch(vi arr, int l, int r, int x) { 
if (r >= l) { int mid = l + (r - l) / 2; if (arr[mid] == x) return mid; 
if (arr[mid] > x)  return binarySearch(arr, l, mid - 1, x); 
return binarySearch(arr, mid + 1, r, x); } return -1; } 
bool sortGrt(const pair<int,int> &a, const pair<int,int> &b) 
{ 
    return (a.second > b.second);  
} 

void solve(int test)
{
  int n;cin>>n;
  vi a(n);
  scan(a,n);
  sort(all(a));
  int suffix[n]={0};
  suffix[n-1]=0;
  for(int i=n-2;i>=0;i--)
  {
    suffix[i]=suffix[i+1]+a[i+1];
  }
  // loop(i,0,n)
  // cout<<suffix[i]<<" ";
  // cout<<endl;
  int t1=0;
  for(int i=0;i<n;i++)
  {
    t1+=(a[i]*a[i]);
  }
  t1=t1* (n-1);

  int t2=0;
  loop(i,0,n)
  {
    t2+= a[i]*suffix[i];
  }
  t2*=2;

  t1=t1-t2;

  cout<<t1;
}

int32_t main()
{
      #ifndef ONLINE_JUDGE
          freopen("input.txt", "r", stdin);
          freopen("output.txt", "w", stdout);
      #endif
      faster;
      //fact(mod);
      int t=1;
      //cin>>t;
      for(int test=1;test<=t;test++)
      {
          solve(test);
      }
}
#include <bits/stdc++.h>
using namespace std;

struct Fast {Fast() {std::cin.tie(0); ios::sync_with_stdio(false);}} fast;

using ull = unsigned long long;
using ll = long long;
using vi = vector<int>;
using vl = vector<long>;
using vll = vector<long long>;
using vvi = vector<vi>;
using vvl = vector<vl>;
using vvll = vector<vll>;
using vs = vector<string>;
using pii = pair<int, int>;

#define pb push_back
#define mp make_pair
#define YESNO(bool) if(bool){cout<<"YES"<<endl;}else{cout<<"NO"<<endl;}
#define yesno(bool) if(bool){cout<<"yes"<<endl;}else{cout<<"no"<<endl;}
#define YesNo(bool) if(bool){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}

#define reps(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define rep(i, n) reps(i, 0, n)
#define rrep(i, n) reps(i, 1, n + 1)
#define repd(i,n) for(ll i=n-1;i>=0;i--)
#define rrepd(i,n) for(ll i=n;i>=1;i--)

#define debug(x) cerr << "\033[33m(line:" << __LINE__ << ") " << #x << ": " << x << "\033[m" <<endl;

inline int in_int() {int x; cin >> x; return x;}
inline ll in_ll() {ll x; cin >> x; return x;}
inline string in_str() {string x; cin >> x; return x;}
template <typename T> inline bool chmin(T& a, const T& b) {bool compare = a > b; if (a > b) a = b; return compare;}
template <typename T> inline bool chmax(T& a, const T& b) {bool compare = a < b; if (a < b) a = b; return compare;}

int main()
{
    int n = in_int();
    ll ret = 0;
    ll x = 0;
    ll y = 0;
    rep(i, n) {
        int a = in_int();
        ret += i * a * a - 2 * a * x + y;
        x += a;
        y += a * a;
    }
    //reps(i, 1, n) {
    //    rep(j, i) {
    //        ret += (a[i] - a[j]) * (a[i] - a[j]);
    //    }
    //}
    cout << ret;
    return 0;
}
