#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> v;
  int q;
  cin >> q;
  unsigned long long int sum;
  unsigned long int a, n;
  while (q--) {
    cin >> n;
    sum = 0;
    for (unsigned int i = 0; i < n; i++) {
      cin >> a;
      sum = sum + a;
    }
    sum %= n;
    cout << sum * (n - sum);
  }
}
