#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;

#define getmid(l,r) ((l) + ((r) - (l)) / 2)
#define MEM(a,b) memset(a,b,sizeof(a))
#define MP(a,b) make_pair(a,b)
#define PB push_back
#define X first
#define Y second

typedef long long ll;
typedef pair<ll,ll> pll;
const double eps = 1e-8;
const int INF = (1 << 30) - 1;
const int MAXN = 100;

ll C[40][40];
int T,n,A[MAXN];

int main(){
    for(int i = 0; i < 40; ++i){
        C[i][0] = C[i][i] = 1;
        for(int j = 1; j < i; ++j){
            C[i][j] = C[i - 1][j] + C[i - 1][j - 1];
        }
    }
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for(int i = 1; i <= n; ++i){
            scanf("%d",&A[i]);
        }
        sort(A + 1,A + n + 1);
        ll odd = 0,even = 0;
        for(int i = 1; i <= n; ++i){
            int rem = n - i;
            for(int j = 0; j <= rem; j += 2){
                odd += 1ll * A[i] * C[rem][j];
            }
            for(int j = 1; j <= rem; j += 2){
                even += 1ll * A[i] * C[rem][j];
            }
        }
        ll ans = odd - even;
        if(ans < 0) ans = -ans;
        printf("%I64d\n",ans);
    }
    return 0;
}