#include<bits/stdc++.h>   using namespace std;       #define FIO             ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)   mt19937                 rng(chrono::steady_clock::now().time_since_epoch().count());   #define endl              n    #define mp              make_pair   #define pb              push_back   #define ins             insert   #define lb              lower_bound   #define ub              upper_bound   #define ff              first   #define ss              second   #define sz(x)           (ll)(x).size()   #define vi              vector<int>   #define mt              make_tuple   #define mii             map<int,int>   #define um              unordered_map<int,int>   #define pii             pair<int,int>     #define maxpq           priority_queue<int>   #define minpq           priority_queue<int,vi,greater<int>>   #define setbits(x)      __builtin_popcountll(x)   #define ps(x,y)         fixed<<setprecision(y)<<x   #define all(x)          x.begin(), x.end()   #define allr(x)         rbegin(x), rend(x)   #define w(x)            int x; cin>>x; while(x--)     #define goog(tno)       cout <<  Case #  << tno << :     #define trace(x)        cerr<<#x<< :  <<x<<   <<endl;       typedef long double ld;   #define ll  long long int   #define ull unsigned ll   const int MOD = 1000000007;   const ll INF = 1e18;   const ld pi =3.14159265359;    // const int mod = 1000003;       template <class T> ll maxpower(T a , T b){ll ans = 0;while(a > 0 && a % b == 0){ans++;a /= b;}return ans;}   template <class T> T mceil(T a, T b){if(a % b == 0) return a/b; else return a/b + 1;}       //---------------------------------------------------------------------------   // cin>> vector<T>   template <class T> istream &operator>>(istream &in, vector<T> &a){for (auto &i : a)cin >> i;return in;}   // cout << vector<T>   template <class T> ostream &operator<<(ostream &ostream, const vector<T> &c){for (auto &it : c) cout << it <<    ;return ostream;}   //---------------------------------------------------------------------------       void __print(int x) {cerr << x;}   void __print(long x) {cerr << x;}   void __print(long long x) {cerr << x;}   void __print(unsigned x) {cerr << x;}   void __print(unsigned long x) {cerr << x;}   void __print(unsigned long long x) {cerr << x;}   void __print(float x) {cerr << x;}   void __print(double x) {cerr << x;}   void __print(long double x) {cerr << x;}   void __print(char x) {cerr <<      << x <<     ;}   void __print(const char *x) {cerr <<     << x <<    ;}   void __print(const string &x) {cerr <<     << x <<    ;}   void __print(bool x) {cerr << (x ?  true  :  false );}       template<typename T, typename V>   void __print(const pair<T, V> &x) {cerr <<  { ; __print(x.first); cerr <<  , ; __print(x.second); cerr <<  } ;}   template<typename T>   void __print(const T &x) {int f = 0; cerr <<  { ; for (auto &i: x) cerr << (f++ ?  ,  :   ), __print(i); cerr <<  } ;}   void _print() {cerr <<  ] n ;}   template <typename T, typename... V>   void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr <<  ,  ; _print(v...);}       #ifndef ONLINE_JUDGE   #define debug(x...) cerr <<  [  << #x <<  ] = [ ; _print(x)   #else   #define debug(x...)   #endif      int main(){       FIO;       w(t){           ll n;           cin>>n;              ll sum = 0;              for(ll i=0;i<n;i++){               ll x;               cin>>x;                  sum += x;           }              cout<<sum%n*(n-sum%n)<<endl;       }   }