#include <bits/stdc++.h>
#define TASK ""
#define FAST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define READFILE freopen(TASK".INP","r",stdin)
#define WRITEFILE freopen(TASK".OUT","w",stdout)
#define For(i,a,b) for(int i=a;i<=b;i++)
#define Rep(i,a,b) for(int i=a;i>=b;i--)
#define pb push_back
#define popb pop_back
#define pf push_front
#define popf pop_front
#define ENDL '\n'
#define debug(x) cout<<#x<<" = "<<x<<ENDL
#define fi first
#define se second
#define ever (;true;)
#define all(x) x.begin(),x.end()
#define sz(a) ((int)(a).size())
#define ms(a,x) memset(a,x,sizeof(a))
#define int long long

using namespace std;
typedef vector <int> vi;
typedef pair <int,int> ii;
typedef vector <ii> vpi;
typedef pair <int,ii> iii;
const int N = 100010;
const int oo=0x3f;
const int mod=1e9+7;
const int dx[]={0,1,0,-1,0};
const int base=311;
const double EP=1e-9;
int t,n,a[N];
void sol(){
    cin >> n;
    ms(a,0);
    For(i,1,3*n) cin >> a[i];
    sort(a+1,a+1+3*n);
    vi c;
    vi b;
    Rep(i,n*3,n+1){
        b.pb(a[i]);
        i--;
        c.pb(a[i]);
    }
    int ans=0;
    For(i,1,n){
        ans+=(b[i-1]-a[i])*c[i-1];
    }
    cout << ans;
}
void init(){
  FAST;
  if (fopen(TASK".INP","r")){
    READFILE;
    WRITEFILE;
  }
  cin >> t;
}
signed main()
{
  init();
  while (t--) sol();
  return 0;
}