#include<bits/stdc++.h>
using namespace std;
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);
#define int long long
#define ld long double
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define rep(i,x,y) for(int i=x; i<y; i++)
#define fill(a,b) memset(a,b,sizeof(a))
#define vi vector<int>
#define vii vector<pair<int,int>>
#define setbits(x) __builtin_popcountll(x)
#define w(x)  int x; cin>>x; while(x--)
#define in(a) for(auto &x: a)cin>>x;
#define out(a) for(auto x: a){cout<<x<<' ';}cout<<'\n';
#define inf 1000000000
//#define mm 1000000007 998244353
void print(bool n){if(n)cout<<"YES";else cout<<"NO";cout<<'\n';}
signed main(){
	fastio
	w(t){
		int s=0;
		int n;
		cin>>n;
		int a[n];
		in(a);
		rep(i,0,n)s+=a[i];
		int x=(s/n)*n;
		int r;
		if(x==0)r=s;
		else r=s%x;
		cout<<(int)r*(n-r)<<'\n';
	}
	return 0;
}