#include<bits/stdc++.h>
using namespace std;
struct node
{
	int x,y;
}s[1005][1005];
int main()
{
	int n,m,cx,cy;
	cin>>n>>m>>cx>>cy;
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=m;j++)
		{
			cin>>s[i][j].x>>s[i][j].y;
		}
	}
	while(s[cx][cy].x!=0||s[cx][cy].y!=0)
	{
		cout<<cx<<" "<<cy<<endl;
		int q=cx;
		cx=s[cx][cy].x;
		cy=s[q][cy].y;
	}
	cout<<cx<<" "<<cy<<endl;
	return 0;
}