#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
#define INF 0x3f3f3f3f
#define eps 1e-8
typedef long long LL;

LL odd, even, a[35], f[35][35];

int main()
{
    memset(f, 0, sizeof(f));
    for (int i = 0; i <= 30; i++)
        f[0][i] = 1;
    for (int i = 1; i <= 30; i++)
    for (int j = 1; j <= i; j++)
        f[j][i] = f[j-1][i-1] + f[j][i-1];
    int t, n;
    scanf("%d", &t);
    while (t--)
    {
        odd = even = 0;
        scanf("%d", &n);
        for (int i = 0; i < n; i++)
            scanf("%I64d", &a[i]);
        sort(a, a+n);
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < n-i; j += 2)
                odd += a[i] * f[j][n-i-1];
            for (int j = 1; j < n-i; j += 2)
                even += a[i] * f[j][n-i-1];
        }
        printf("%I64d\n", abs(odd-even));
    }
    return 0;
}