#include <bits/stdc++.h>
using namespace std;
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
int dx8[] = {0, 0, 1, 1, 1, -1, -1, -1};
int dy8[] = {1, -1, -1, 0, 1, -1, 0, 1};
int kx8[] = {1, 1, 2, 2, -1, -1, -2, -2};
int ky8[] = {2, -2, 1, -1, 2, -2, 1, -1};
long long bigmod(long long a, long long b, long long c) {
  if (b == 0) return 1 % c;
  long long x = bigmod(a, b / 2, c);
  x = (x * x) % c;
  if (b % 2 == 1) x = (x * a) % c;
  return x;
}
long long poww(long long a, long long b) {
  if (b == 0) return 1;
  long long x = poww(a, b / 2);
  x = x * x;
  if (b % 2 == 1) x = (x * a);
  return x;
}
long long mod_inverse(long long a, long long mod) {
  return bigmod(a, mod - 2, mod);
}
vector<long long> a, b;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> n;
  long long sumx = 0, sumy = 0;
  for (int i = 0; i < (n); i++) {
    int x, y;
    cin >> x >> y;
    sumx += x;
    sumy += y;
    a.push_back(x);
    b.push_back(y);
  }
  long long res = 0, sum = 0;
  for (auto x : a) {
    res += 2 * x * x * n - 2LL * x * (sumx);
  }
  sum = 0;
  for (auto x : b) {
    res += 2 * x * x * n - 2LL * x * (sumy);
  }
  cout << res / 2 << endl;
  return 0;
}
