#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

long long get(int ind,vector<long long> &S1,vector<long long> &S2){
	int n = S1.size()-1;
	//cout<<n<<','<<ind<<endl;
	if(ind==n){
		return S1[n] - S1[n-1];
	}
	if(ind%2==0){
		long long ret = S1.back() - S1[ind];
		ret = max(ret,get(ind+1,S1,S2));
		return ret;
	}
	else{
		long long ret = S2[n-1] - S2[ind];
		ret = min(ret,get(ind+1,S1,S2));
		return ret;
	}
}

int main(){
	int _t;
	cin>>_t;
	
	rep(_,_t){
		int n;
		cin>>n;
		
		vector<long long> a(n);
		rep(i,n)cin>>a[i];
		
		sort(a.begin(),a.end());
		
		vector<long long> S1(n+1,0),S2(n+1,0);
		rep(i,n){
			S1[i+1] = a[i];
			S2[i+1] = a[i];
			if((n-1)%2==i%2){
				S2[i+1] *= -1;
			}
			else{
				S1[i+1] *= -1;
			}
			if(i==n-1){
				S2[i+1] = 0;
			}
			S1[i+1] += S1[i];
			S2[i+1] += S2[i];
		}
		cout<<get(0,S1,S2)<<endl;
	}
	
	return 0;
}