#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=1167167167167167167;
const int INF=2100000000;
const ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}

int f(vector<int> p){
	int N=p.size();
	//if(N==1) return p[0];
	int ans=0;
	int r=N-1,l=N/2;
	rep(i,l+1) ans+=p[i];
	int tmp=ans;
	while(l!=0){
		tmp-=p[l];
		l--;
		tmp+=p[r];
		r-=2;
		chmax(ans,tmp);
	}
	return ans;
}

void solve();
// oddloop
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	cin>>t;
	rep(i,t) solve();
}

void solve(){
	int N;
	cin>>N;
	vector<int> p(N);
	rep(i,N){
		cin>>p[i];
	}
	So(p);
	int S=p[N-1];
	rep(i,N-1){
		p[N-i-1]-=p[N-i-2];
	}
	if(N%2) cout<<f(p)<<"\n";
	else{
		p.resize(N-1);
		cout<<S-f(p)<<"\n";
	}
}