#include <iostream>
using namespace std;

const int N = 100005;

struct point{
    double x,y;
    bool operator<(point&b){return y<b.y || y==b.y && x<b.x;}
};

int n,m,d;
int i,j,k;
point p1[N], p2[N], s[N*2];
bool u1[N], u2[N];

void add(point&b, point&a){
    s[d].x = s[d-1].x+(a.x-b.x);
    s[d].y = s[d-1].y+(a.y-b.y);
    ++d;
}

int main(){

    cin>>n>>m;
    for(i=0;i<n;++i) cin>>p1[i].x>>p1[i].y;
    for(i=0;i<m;++i) cin>>p2[i].x>>p2[i].y;

    p1[n]=p1[0];
    p2[m]=p2[0];

    for(i=k=0;k<n;++k) if(p1[k]<p1[i]) i=k;
    for(j=k=0;k<m;++k) if(p2[k]<p2[j]) j=k;

    d=1;
    s[0].x = p1[i].x+p2[j].x;
    s[0].y = p1[i].y+p2[j].y;


    for(;;){
        if(i==n) i=0;
        if(j==m) j=0;
        if(u1[i] && u2[j]) break;

        if(u1[i] || !u2[j] && (p1[i+1].x-p1[i].x)*(p2[j+1].y-p2[j].y)-(p1[i+1].y-p1[i].y)*(p2[j+1].x-p2[j].x)<0){
            add(p2[j], p2[j+1]);
            u2[j]=true;
            ++j;
        }else{
            add(p1[i], p1[i+1]);
            u1[i]=true;
            ++i;
        }
    }


    for(i=0;i<d-1;++i){
        cout<<s[i].x<<' '<<s[i].y<<endl;
    }

    return 0;
}