#include<bits/stdc++.h>
using namespace std;

#define int long long

const int N=1e2+1e1+7;

struct P{
    int x,y;
    P(int _x=0,int _y=0){x=_x,y=_y;}
};

P operator *(const P &a,const int &b)
{
    return {a.x*b,a.y*b};
}

P operator -(const P &a,const P &b)
{
    return {a.x-b.x,a.y-b.y};
}

P operator +(const P &a,const P &b)
{
    return {a.x+b.x,a.y+b.y};
}

int T;

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>T;
    while(T--)
    {
        int n;
        cin>>n;
        vector<P>p(n);
        for(auto &[x,y]:p)
            cin>>x>>y,x*=2,y*=2;
        sort(p.begin(),p.end(),[&](const P &a,const P &b){
            if(a.y!=b.y)
                return a.y<b.y;
            return a.x<b.x;
        });
        int h=n/2;
        P m=(p[h-1]+p[h]);
        m.x/=2,m.y/=2;
        vector<pair<P,P> >ans;
        P A=m+P(1e8,0);
        P B=m+P(-1e8,0);
        if(p[h-1].y==p[h].y)
            A.y+=5,B.y-=5;
        ans.push_back({A,B});
        int u=0,v=h;
        while(u+1<=h-1&&v+1<=n-1)
        {
            P a=p[u],b=p[u+1];
            P c=p[v],d=p[v+1];
            P mab=a+b;
            mab.x/=2,mab.y/=2;
            P mcd=c+d;
            mcd.x/=2,mcd.y/=2;
            P dir=mab-mcd;
            mab=mab+dir*100000;
            mcd=mcd-dir*100000;
            mcd.x+=5;
            mab.x-=5;
            ans.push_back({mab,mcd});
            u++,v++;
        }
        if(n&1)
        {
            P a=p[v],b=p[v+1];
            P m=(a+b);
            m.x/=2,m.y/=2;
            P A=P(m.x,1e8),B=P(m.x,-1e8);
            A.x+=5;
            B.x-=5;
            ans.push_back({A,B});
        }
        for(auto [a,b]:ans)
        {
            a.x/=2;
            a.y/=2;
            b.x/=2;
            b.y/=2;
            cout<<a.x<<" "<<a.y<<" "<<b.x<<" "<<b.y<<"\n";
        }
    }
}