#include<algorithm>
#include<iostream>
#include<iomanip>
#include<cstring>
#include<cstdlib>
#include<complex>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include<cmath>
#include<deque>
#include<map>
#include<set>
#define oo 1000000000
#define ooll (1ll<<50)
#define base 1000000007ll
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
                            /*                           END OF TEMPLATE                            */
//IOI 2014
int R,C,n,m,ans,BIT[10000005];
ii nans;
vector<ii> row[1000005],col[1000005];
vector<ii> qry[2][1000005];
vector<int> open[2][1000005],close[2][1000005];
void update(int x,int w) { for(; x<=C; x+=x&(-x)) BIT[x]+=w; }
int query(int x)
{
    int res=0;
    for(; x; x=x&(x-1)) res+=BIT[x];
    return res;
}
ii mn(ii u,ii v)
{
    if(u.first==v.first) return u.second<v.second?u:v;
    return u.first<v.first?u:v;
}
void solve(int t)
{
    bool fb=false;
    for(int i=1; i<=R; i++)
    {
        for(int j=0; j<open[t][i].size(); j++) update(open[t][i][j],1);
        sort(qry[!t][i].begin(),qry[!t][i].end());
        for(int j=0; j<qry[!t][i].size(); j++)
        {
            ii x=qry[!t][i][j];
            int d=query(x.second)-query(x.first-1);
            ans+=d;
            if(d && !fb)
            {
                fb=true;
                for(int k=x.first; k<=x.second; k++)
                    if(query(k)!=query(k-1))
                    {
                        nans=mn(nans,ii(i,k));
                        break;
                    }
            }
        }
        for(int j=0; j<close[t][i].size(); j++) update(close[t][i][j],-1);
    }
}
bool dfs(int u,int v,int dir,int t)
{
    int nu=u,nv=v,ndir;
    ii x;
    if(dir==0)
    {
        x=*(lower_bound(row[u].begin(),row[u].end(),ii(v,0))-1);
        nv=x.first;
        if(nv+1<v) qry[t][u].push_back(ii(nv+1,v-1));
        ndir=x.second?1:3;
    }
    if(dir==2)
    {
        x=*upper_bound(row[u].begin(),row[u].end(),ii(v,1));
        nv=x.first;
        if(v+1<nv) qry[t][u].push_back(ii(v+1,nv-1));
        ndir=x.second?3:1;
    }
    if(dir==1)
    {
        x=*(lower_bound(col[v].begin(),col[v].end(),ii(v,0))-1);
        nu=x.first;
        if(nu+1<u)
        {
            open[t][nu+1].push_back(v);
            close[t][u-1].push_back(v);
        }
        ndir=x.second?0:2;
    }
    if(dir==3)
    {
        x=*upper_bound(col[v].begin(),col[v].end(),ii(u,1));
        nu=x.first;
        if(u+1<nu)
        {
            open[t][u+1].push_back(v);
            close[t][nu-1].push_back(v);
        }
        ndir=x.second?2:0;
    }
    if(nu>=1 && nu<=R && nv>=1 && nv<=C) return dfs(nu,nv,ndir,t);
    return nu==R && nv==C+1;
}
int main()
{
    freopen("laser.inp","r",stdin);
    freopen("laser.out","w",stdout);
    int u,v;
    scanf("%d %d %d %d",&R,&C,&n,&m);
    nans=ii(R,C);
    for(int i=1; i<=n; i++)
    {
        scanf("%d %d",&u,&v);
        row[u].push_back(ii(v,0));
        col[v].push_back(ii(u,0));
    }
    for(int i=1; i<=m; i++)
    {
        scanf("%d %d",&u,&v);
        row[u].push_back(ii(v,1));
        col[v].push_back(ii(u,1));
    }
    for(int i=1; i<=R; i++)
    {
        row[i].push_back(ii(0,0));
        row[i].push_back(ii(C+1,0));
        sort(row[i].begin(),row[i].end());
    }
    for(int i=1; i<=C; i++)
    {
        col[i].push_back(ii(0,0));
        col[i].push_back(ii(R+1,0));
        sort(col[i].begin(),col[i].end());
    }
    if(dfs(1,0,2,0))
    {
        printf("0\n");
        return 0;
    }
    dfs(R,C+1,0,1);
    solve(0);
    solve(1);
    if(ans==0) printf("Impossible\n");
    else printf("%d %d %d\n",ans,nans.first,nans.second);
    return 0;
}