#include<bits/stdc++.h>
using namespace std;
#define endl '\n'
typedef long long ll;
typedef long double ld; 
#define endl '\n'
#define sz(x) (int)(x).size()
#define all(t) (t).begin(), (t).end()
#define rep(i, a, b) for (ll i = (a); i <= (b); ++i)
#define per(i, a, b) for(ll i = (a); i >= (b); --i)
#define debug(x) cout<<#x<<": "<<x<<endl
const int N=2e5+10,M=1e6+10;
const ld eps=1e-12; 
#define double long double

int sgn(double x)
{
	if(fabs(x)<eps) return 0;
	return x>0?1:-1;
}

typedef struct point
{
	double x,y;
	point(double x=0,double y=0) :x(x),y(y){}
	point operator - (point b) {return point(x-b.x,y-b.y);}
	double operator ^ (point b) {return x*b.y-y*b.x;}
	bool operator < (const point &b) const {return sgn(x-b.x)==0?sgn(y-b.y)<0:x<b.x;}
	bool operator == (const point &b) const {return sgn(x-b.x)==0&&sgn(y-b.y)==0;}
}Vector;

typedef struct line
{
	point s,e;
	line(point s1,point e1) {s=s1,e=e1;}
}seg;

double cross(point a,point b,point c) {return (b-a)^(c-a);}

struct polygon
{
	int n=0;
	vector<point>p;
	vector<line>l;
	void add(point x){p.push_back(x),n++;}
	void getline()
	{
		for(int i=0;i<n;i++)
			l.push_back(line(p[i],p[(i+1)%n]));
	}
	vector<point> Andrew()
	{
		vector<point>s;
		sort(p.begin(),p.end());
		for(int i=0;i<n;i++)
		{
			while(s.size()>1&&cross(s[s.size()-2],s[s.size()-1],p[i])<=0) s.pop_back();
			s.push_back(p[i]);
		}
		int t=s.size();
		for(int i=n-2;i>=0;i--)
		{
			while(s.size()>t&&cross(s[s.size()-2],s[s.size()-1],p[i])<=0) s.pop_back();
			s.push_back(p[i]);
		}
		if(s.size()>1) s.pop_back();
		p=s,n=s.size();
		return s;
	}
	double area()
	{
		double sum=0;
		for(int i=0;i<n;i++) sum+=p[i]^p[(i+1)%n];
		return fabs(sum)/2;
	}
};

double area(line l,point p)
{
	return fabs((p-l.s)^(l.e-l.s))/2;
}

void solve() 
{
	int n;
	cin>>n;
	vector<point>p;
	polygon yuan;
	for(int i=1;i<=n;i++)
	{
		ll x,y;
		cin>>x>>y;

		p.push_back(point(x,y));
		yuan.add(p[i-1]);
	}
	map<pair<double,double>,int>mp;
	vector<point>f=yuan.Andrew();
	polygon F,G;
	for(auto p:f) F.add(p),mp[{p.x,p.y}] = 1;
	F.Andrew();
	double ans=F.area();
	// debug(ans);
	for(auto u:p) if(!mp.count({u.x,u.y})) G.add(u);
	G.Andrew();
	F.getline();
	vector<seg>l=F.l;
	n=l.size();
	// debug(l.size());

	vector<point>np=G.p;
		// for(auto u:np) debug(u.x),debug(u.y);
	int m=np.size();
	// debug(m);
	if(m==0)
	{
		cout<<-1<<endl;
		return;
	}
	int pp=0;
	double minn=area(l[0],np[pp]);
	
	for(int i=1;i<m;i++)
	{
		if(area(l[0],np[i])<minn)
		{
			minn=area(l[0],np[i]);
			pp=i;
		}
	};
	for(int pl=1;pl<n;pl++)
	{
		while(1)
		{
			if(area(l[pl],np[pp])<=area(l[pl],np[(pp+1)%m])) break;
			else pp++, pp %= m;
		}
		// if(!area(l[pl],np[pp])) {
		// 	debug(l[pl].e.x);
		// 	debug(l[pl].e.y);
		// 	debug(l[pl].s.x);
		// 	debug(l[pl].s.y);
		// 	debug(np[pp].x);
		// 	debug(np[pp].y);
		// 	debug(np.size());
		// 	debug(pp);
		// 	exit(0);
		// }
		minn=min(minn,area(l[pl],np[pp]));
	}
	cout<<fixed << setprecision(0)<<2*(ans-minn)<<endl;
}

int main() 
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
	 cin >> T;
	//	cout.flush();
	//		ofstream outfile("C:\\Users\\86187\\OneDrive\\桌面\\1.txt");
	//		outfile << "a[1]=0;a[2]=1;";
	//		ll l = 1e7 + 1;
	//		rep(i, 3, 1e9) {
	//			printf("%lld\n", i);
	//			ll x = (i - 1) * ((a[i - 1] + a[i - 2]) % mod);
	//			x %= mod;
	//			if(i == l) {
	//				outfile << "a[" << i << "]=" << x << ";";
	//			}
	//			if(i == l + 1) {
	//				outfile << "a[" << i << "]=" << x << ";";
	//				l += 1e7;
	//			}
	//		}
	while(T--) {
		solve();
	}
	return 0;
}