#include<bits/stdc++.h>
#define inf 0x3f3f3f3f3f3f3f3fll
#define debug(x) cerr<<#x<<"="<<x<<endl
using namespace std;
using ll=long long;
using ld=long double;
using pli=pair<ll,int>;
using pi=pair<int,int>;
template<typename A>
using vc=vector<A>;
inline int read()
{
    int s=0,w=1;char ch;
    while((ch=getchar())>'9'||ch<'0') if(ch=='-') w=-1;
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
inline ll lread()
{
    ll s=0,w=1;char ch;
    while((ch=getchar())>'9'||ch<'0') if(ch=='-') w=-1;
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
struct node
{
    int x,y;
    int id;
}a[10001];
int ty[10001];
vc<int>v1[10001],v2[10001];
int x[10001],y[10001];
int num1[10001],c1;
int num2[10001],c2;
vc<pi>ans1,ans2;
int n,m,c;
inline ll X(int p,int q){ return x[q]-x[p];}
inline ll Y(int p,int q){ return y[q]-y[p];}
inline ll cha(int a,int b,int c)
{
    return X(a,b)*Y(a,c)-X(a,c)*Y(a,b);
}
inline void init()
{
    //左上->右下凸壳
    sort(a+1,a+c+1,[](node a,node b){ return a.x==b.x?a.y>b.y:a.x<b.x;});
    for(int i=1;i<=c;i++)
    {
        int u=a[i].id;
        while(c1>=2)
        {
            int p=num1[c1-1],q=num1[c1];
            if(Y(p,q)*X(q,u)<Y(q,u)*X(p,q)) c1--;
            else break;
        }
        num1[++c1]=u;
    }
    //右下->左上凸壳
    sort(a+1,a+c+1,[](node a,node b){ return a.x==b.x?a.y<b.y:a.x>b.x;});
    for(int i=1;i<=c;i++)
    {
        int u=a[i].id;
        while(c2>=2)
        {
            int p=num2[c2-1],q=num2[c2];
            if(Y(p,q)*X(q,u)<Y(q,u)*X(p,q)) c2--;
            else break;
        }
        num2[++c2]=u;
    }

    // for(int i=1;i<=c1;i++) printf("%d%c",num1[i]," \n"[i==c1]);
    // for(int i=1;i<=c2;i++) printf("%d%c",num2[i]," \n"[i==c2]);
}
inline void push(int x,int y)
{
    if(x<=n) ans1.push_back(pi(x,y));
    else ans2.push_back(pi(x-n,y-n));
}
inline bool ro(int A,int B,int C){ return cha(A,B,C)>0;}
inline bool tri(int A,int B,int C,int p)
{
    bool f=1;
    if(ro(A,B,p)==ro(A,C,p)) f=0;
    if(ro(B,A,p)==ro(B,C,p)) f=0;
    if(ro(C,A,p)==ro(C,B,p)) f=0;
    return f;
}
inline void run(int A,int B,int C,vc<int>sa,vc<int>sb)
{
    if(sa.size())
    {
        int p=sa[0];push(A,p);
        vc<int>v1,v2,v3,v4,v5,v6;
        for(int q:sa) if(q!=p)
        {
            if(tri(A,B,p,q)) v1.push_back(q);
            else if(tri(A,C,p,q)) v3.push_back(q);
            else v5.push_back(q);
        }
        for(int q:sb)
        {
            if(tri(A,B,p,q)) v2.push_back(q);
            else if(tri(A,C,p,q)) v4.push_back(q);
            else v6.push_back(q);
        }
        run(B,A,p,v2,v1);
        run(C,A,p,v4,v3);
        run(p,B,C,v5,v6);
    }
    else
    {
        for(int i:sb) push(B,i);
    }
}
inline bool checkc(int p)
{
    for(int i=1;i<c1;i++) if(p==num1[i]) return true;
    for(int i=1;i<c2;i++) if(p==num2[i]) return true;
    return false;
}
inline int get(int p,int id)
{
    if(checkc(p)) return -1;
    for(int i=1;i<c1;i++) if(tri(num1[i],num1[i+1],id,p)) return num1[i];
    for(int i=1;i<c2;i++) if(tri(num2[i],num2[i+1],id,p)) return num2[i];
    assert(0);return 114514;
}
inline int wtf(int p,int id,vc<int>&nod1,vc<int>&nod2)
{
    for(unsigned i=1;i<nod1.size();i++) if(tri(nod1[i-1],nod1[i],id,p)) return nod1[i-1];
    if(tri(nod1.back(),nod2[0],id,p)) return nod1.back();
    return nod2[0];
}
inline void run(vc<int>nod1,vc<int>nod2,int f3,int s)
{
    if(f3==-1)
    {
        for(int i=1;i<=c;i++) if(ty[i]==s) push(nod1[0],i);
    }
    else
    {
        // printf("f3=%d\n",f3);
        push(f3,nod2[0]);
        for(int i=1;i<=c;i++) if(ty[i]==s&&i!=f3)
        {
            int f=wtf(i,f3,nod1,nod2);
            if((i<=n)==(f3<=n)) v1[f].push_back(i);
            else v2[f].push_back(i);
            // printf("i=%d : f=%d\n",i,f);
        }
        for(unsigned i=1;i<nod1.size();i++)
        {
            run(f3,nod1[i-1],nod1[i],v1[nod1[i-1]],v2[nod1[i-1]]);
            v1[nod1[i-1]].clear(),v2[nod1[i-1]].clear();
        }
        run(nod1.back(),f3,nod2[0],v2[nod1.back()],v1[nod1.back()]);
        v2[nod1.back()].clear(),v2[nod1.back()].clear();
        run(nod1[0],f3,nod2[0],v2[nod2[0]],v1[nod2[0]]);
        v2[nod2[0]].clear(),v1[nod2[0]].clear();
    }
}
int main()
{
    n=read(),m=read();c=n+m;
    for(int i=1;i<=c;i++) a[i].x=x[i]=read(),a[i].y=y[i]=read(),a[i].id=i;

    init();

    int cnt=0;vc<int>nod1,nod2;
    for(int i=1;i<c1;i++)
    {
        if(cnt) num1[i]<=n?nod1.push_back(num1[i]):nod2.push_back(num1[i]);
        cnt+=(num1[i]<=n)!=(num1[i+1]<=n);
    }
    for(int i=1;i<c2;i++)
    {
        if(cnt) num2[i]<=n?nod1.push_back(num2[i]):nod2.push_back(num2[i]);
        cnt+=(num2[i]<=n)!=(num2[i+1]<=n);
    }
    // if(c==100) cout<<cnt<<endl;
    if(cnt>2)
    {
        printf("Impossible\n");
        return 0;
    }
    if(!cnt)
    {
        //先把外围连起来
        for(int i=1;i<c1;i++) push(num1[i],num1[i+1]);
        for(int i=2;i<c2;i++) push(num2[i],num2[i+1]);
        int id=num1[1]<=n?n+1:1;
        for(int i=1;i<=c;i++) if(i!=id)
        {
            int f=get(i,id);if(f==-1) continue;
            if((i<=n)==(id<=n)) v1[f].push_back(i);
            else v2[f].push_back(i);
        }
        for(int i=1;i<c1;i++) run(id,num1[i],num1[i+1],v1[num1[i]],v2[num1[i]]);
        for(int i=1;i<c2;i++) run(id,num2[i],num2[i+1],v1[num2[i]],v2[num2[i]]);
    }
    else
    {
        cnt=0;
        for(int i=1;i<c1;i++)
        {
            if(!cnt) num1[i]<=n?nod1.push_back(num1[i]):nod2.push_back(num1[i]);
            cnt+=(num1[i]<=n)!=(num1[i+1]<=n);
        }
        for(int i=1;i<c2;i++)
        {
            if(!cnt) num2[i]<=n?nod1.push_back(num2[i]):nod2.push_back(num2[i]);
            cnt+=(num2[i]<=n)!=(num2[i+1]<=n);
        }

        // for(int i:nod1) printf("%d ",i);;putchar('\n');
        // for(int i:nod2) printf("%d ",i);;putchar('\n');

        int f1=nod1[0],f2=nod2[0],f3=-1,f4=-1;
        for(unsigned i=1;i<nod1.size();i++) push(nod1[i-1],nod1[i]);
        for(unsigned i=1;i<nod2.size();i++) push(nod2[i-1],nod2[i]);
        
        for(int i=1;i<=c;i++) if(!checkc(i))
        {
            if(cha(f1,f2,i)>0)
            {
                ty[i]=1;
                if(i>n) f3=i;
            }
            else
            {
                ty[i]=2;
                if(i<=n) f4=i;
            }
            // printf("i=%d ty=%d\n",i,ty[i]);
        }
        run(nod1,nod2,f3,1);
        run(nod2,nod1,f4,2);
    }

    // putchar('\n');
    for(auto i:ans1) printf("%d %d\n",i.first,i.second);
    // putchar('\n');
    for(auto i:ans2) printf("%d %d\n",i.first,i.second);
    return 0;
}
/*
4 5
0 0
0 4
4 6
6 2
8 4
8 0
3 2
4 3
5 1
*/