/*
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⠄⠒⠌⠔⣱⣒⣀⣄⡀⠀⠀⠒⠁⠛⠑⠆⠀⠊⠀⠠⠢⢰⠀⠀⠀⣀⡤⢖⣽⣾⣾⣿⣿⡿⣿⣿
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠂⠀⠀⠀⠀⠀⠀⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠨⠤⢴⣾⣴⣾⣿⣿⢿⣿⣿⣿⣿⡿⠟
⠀⠀⠀⠀⠀⠀⠀⠀⢀⠈⠄⠀⢀⠀⠀⠀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⠠⠀⠀⠀⠀⠀⠀⠀⠀⠈⠛⠿⣿⣷⣿⣻⣿⣿⡿⠛⠁⡀⠄
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠉⡈⠁⣀⠡⠀⡁⠄⢤⡆⠀⡤⠀⡠⠀⠀⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠺⢿⣿⡿⠟⠋⠁⢀⠀⢂⠀⠄
⠀⠀⠀⠀⠀⠀⠀⠰⣒⠊⠁⠠⢀⠢⢁⠐⢆⡰⢯⡊⣆⠄⣀⣀⢀⡕⢀⠔⠀⢰⠂⠀⢀⠀⠀⠀⠀⠀⠀⢖⠋⠀⠠⠐⠈⡀⠐⡀⠄⠂
⠀⠀⠀⠀⠀⠀⠀⢀⣤⣛⠠⣑⡏⣰⡿⢺⢟⡭⠉⠙⡿⠐⢥⠀⠀⠀⠀⠀⠀⠈⢂⠐⠈⠀⠀⠀⠀⠀⠀⢢⡉⠠⠁⠐⠠⠐⠀⠄⠐⡀
⠀⠀⠀⠀⠀⠀⠀⣀⠔⠁⠠⢔⠣⢌⠢⡍⠈⠀⠀⠀⢠⠀⠀⠀⠀⠀⠄⠐⡄⠀⠀⠆⠀⠀⠀⠀⢀⢀⠠⡤⠽⠂⢀⠡⠐⠀⠡⠐⢀⠀
⠀⠀⠀⠀⠀⠀⠀⠉⠉⡹⠀⣤⠣⢌⢢⡁⠀⠀⠀⠀⢸⠀⠀⠀⠀⠀⠆⠀⢲⡀⠀⢠⠀⠂⠀⢔⣥⡛⢤⣶⣤⣐⠀⡀⠂⢁⠐⠀⠂⡀
⠀⠀⠀⠀⠀⠀⠀⠀⠴⠕⡇⢎⡗⣈⡲⠁⠀⠀⢀⡇⢸⠀⠀⠀⠀⠀⢸⠀⠀⠀⠀⢼⠀⠀⢀⡞⣥⣸⣜⣿⣳⠿⣮⣥⣶⣤⣂⠁⠐⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢠⢴⣃⢸⣏⢍⣛⢣⡀⠀⠈⠳⢈⠀⠀⠀⠀⣀⠼⡤⠄⠈⠀⠀⠀⣾⢫⣟⣖⢸⣿⣿⣿⣻⡵⢯⣿⣿⣆⠉⠳⣶
⠴⢻⡒⢦⣠⣀⠤⢔⠈⢀⡀⢿⠽⡜⠟⠻⠿⠓⢤⣄⠘⢱⣤⡶⣛⣁⣤⣇⣠⡤⠀⠀⠀⡧⣾⣟⡿⢸⢛⢿⣿⣷⣻⢻⡾⣍⢏⠳⣄⠈
⠀⠀⠙⠃⠢⢈⠧⡀⢳⡀⢱⡀⢶⢣⡣⢍⢩⡘⠯⢽⠀⠘⠁⠒⠈⠉⠉⢛⠉⠀⠀⠀⠀⣧⡞⣯⣼⡯⢌⠎⣿⣷⢯⣟⡽⣿⢘⣿⣿⣷
⠀⠀⠀⠀⠀⠉⠰⠌⡆⣷⠈⡆⠉⢰⣷⣊⠴⠡⠎⡽⠀⠀⠀⠀⠀⠀⠀⢸⠀⠀⠀⠀⠀⢾⢻⣿⢹⠀⠈⢎⣿⣿⣻⢮⣟⣧⣿⣿⣿⢿
⡼⡳⡄⢀⡶⡀⠨⡁⠓⡄⡒⣏⣾⢻⣽⣷⡊⡕⢣⠹⢤⡤⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⢟⣸⢿⢸⢀⠀⠘⣿⣿⣽⣻⢾⣽⡏⡕⣯⠞
⣙⠻⣧⢸⣗⣣⠀⢸⣴⣷⡟⣯⠷⠛⣼⡿⣿⡜⢤⠓⣼⠤⠄⠀⠠⠀⡀⠀⠀⠀⣠⠔⡱⣪⠞⠘⠈⠁⠀⠀⣿⣿⡷⣯⣟⣾⣗⢷⢸⡹
⠈⣽⡟⠈⠷⠏⢠⣟⣿⠗⠋⠁⠀⣼⡿⣽⣳⣿⣦⡙⣌⢒⠲⠲⠤⠀⠀⢀⡤⡚⡔⣊⡱⠋⡂⠀⠀⠀⠀⠀⣽⣿⣟⣷⣻⣞⣿⣸⠀⣹
⣴⡿⠗⣦⡀⠀⢠⡟⠁⠀⠀⠀⣼⡿⣽⣳⣿⣿⣿⣧⣜⢢⡆⣀⣀⡴⠞⣍⠲⡱⢘⡤⠁⡜⠀⠀⠀⡄⠀⠀⣾⣿⣿⣳⣟⣾⣻⣏⠀⢰
⡟⡴⢂⠈⢧⠜⣫⣾⣶⣄⠀⣸⣿⣽⣳⣯⣿⣿⣿⣿⣿⣏⠹⣹⣶⣉⠞⣠⢣⡕⠉⢀⣼⠃⠀⠀⠀⣻⡄⠀⣻⣿⣿⣿⣞⣷⣻⢿⣿⣦
⣇⠐⠠⡱⢢⣾⣿⣽⣟⣾⣷⣿⣳⢯⣷⡿⢸⣿⣿⣿⣿⣇⢣⠧⡈⠅⠉⠉⠁⠀⢀⣜⠆⠀⠀⠀⠀⢹⡜⣄⣻⣿⣿⣿⣞⡷⣯⣿⣿⣻
⢳⣭⠟⡠⣹⣿⣿⣟⣾⣿⣟⣷⣻⣯⣿⠋⢸⣿⣿⣿⣿⡷⢮⠥⢹⣆⠀⠀⠀⣔⣣⠾⠔⠒⠒⠚⠉⠉⠁⢀⣿⣿⣿⣿⣿⡽⣷⢯⣿⣿
⠀⣿⣸⣴⣿⣿⣳⣿⣿⣳⡿⣾⣽⣯⢻⠀⢸⣿⣿⣿⣿⣇⠻⠀⠀⠈⠁⠀⠈⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸⣿⣿⣿⣿⣿⣿⣻⣟⣷⣿
⣾⣿⣿⣿⣿⣽⣿⣟⣾⢿⣽⠟⣹⠁⢸⠀⢸⣿⣿⣿⣿⡇⣏⠀⠀⠀⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣄⡄⣿⣿⣿⣿⣿⣿⣿⣷⢿⣻⣾
⣿⣿⣿⣿⡿⣯⣷⡿⣯⡿⠋⠀⠀⠀⣸⠀⠰⣿⣿⣿⣿⣏⠼⠀⠀⠀⢰⠀⠀⠀⠀⠀⠀⠀⠀⢀⡄⠀⢠⣿⣿⣿⣿⣿⣿⠇⠻⣟⣯⣿
⣿⣿⣿⢯⣿⡿⣽⡿⠟⡃⠀⡀⠀⠀⡆⠀⠀⣿⣿⣿⣿⡧⢫⡅⠀⠀⠈⡄⠀⠀⠀⠀⠀⠀⠸⠃⠂⠀⣾⣿⣿⣿⣿⣿⡟⠀⡠⢹⢻⣿
⣿⣿⣽⣿⣿⠝⠁⠀⠀⢧⠀⡆⠀⠀⠀⠀⠀⣿⣿⣿⣿⣗⢣⢞⣄⠀⠀⢟⣆⠀⠀⠀⢠⠜⠁⠀⠀⣸⣿⣿⣿⣿⣿⡿⠁⠀⢇⢸⠀⠙
*/
// IAM Batman
//           Vengeance
//                    Maybe im the problem
#include <bits/stdc++.h>
#define ll long long
#define Time cerr << "Time Taken: " << (float)clock() / CLOCKS_PER_SEC << " Secs" \<< "\n";
#define ln cout << endl;
#define c(n) cout << n;
#define fix cout << fixed << setprecision(6);
#define sz(x) int(x.size())
#define loop(n) for (int i = 0; i < n; i++)
#define loop1(n) for (int i = 1; i < n; i++)
#define vi vector<int>
#define vll vector<long long>
#define all(s) s.begin(), s.end()
#define srt(arr, n) sort(arr, arr + n);
#define prefixsum(arr, n)        \
    for (int i = 1; i <= n; i++) \
    {                            \
        arr[i] += arr[i - 1];    \
    }
#define upper(s) transform(all(s), s.begin(), ::toupper);
#define lower(s) transform(all(s), s.begin(), ::tolower);
#define pi 3.141592653
#define pb push_back
#define vc vector<char>
#define sz(s) s.size()
#define supra_mk4 ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
#define ulli unsigned ll int

using namespace std;

void Bassel()
{
    // supra_mk4
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin),
        freopen("output.txt", "w", stdout);
#endif
}

void solve1()
{
    int n;
    cin >> n;
    int a[n];
    int sum = 0;
    loop(n)
    {
        cin >> a[i];
        sum += a[i];
    }
    int avg = sum / n;
    // cout<<"avg:"<<avg<<" ";
    int cost = 0;
    for (int i = 0; i < n; i++)
    {
        cost += pow((a[i] - avg), 2);
    }
    cout << cost << "\n";
}

int main()
{
    Bassel();
    supra_mk4 int t = 1;
    cin >> t;
    while (t--)
    {
        solve1();
    }

    return 0;
}