/// #514
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int > pii;
typedef long long int lld;
#define pi acos(-1)
#define fr(i,m,n) for(i=m;i<n;i++)
#define fu(i,m,n) for(i=m;i>=n;i--)
#define vec vector<lld>
#define pb push_back
#define pp pop_back()
#define ft first
#define sd second
#define all(v) v.begin(),v.end()
#define mom(ara) memset(ara,0,sizeof(ara));
#define m1m(ara) memset(ara,-1,sizeof(ara));
#define endl "\n"
#define eps 1.19209e-07
int main()
{ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
    lld i,j,k,a,b,c,x,y,z,n,m,ans,t;
    cin>>t;
    while(t--)
    {
    	cin>>n;lld sum=0;
    	fr(i,0,n)
    	{
    		cin>>x;
    		sum+=x;
    	}
    	sum%=n;
    	cout<<(n-sum)*sum<<endl;
    }
}