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

struct Location{
	int x[2005];
	int num[2005];
}a[1001];

int main(){
	int m,n,Sx,Sy;
	cin >> m >> n >> Sx >> Sy;
	int o = Sx;
	int p = Sy;
	for(int i = 0;i < n;i++){
		for(int j = 0;j < 2*m;j++){
			cin >> a[i].x[j];
		}
	}
	
	for(int i = 0;i < n;i++){   // 1, 2
		for(int j = 0;j < 2*m;j++){
			if(i+1 == Sx && j + 1 == Sy*2 - 1){ // 确定任务指引数 // 1,2 sx=1 
				if(a[i].x[j] == 0 && a[i].x[j+1] ==0){
					a[i].num[j] = 2;
					a[i].num[j+1] = 2;
					break;
				} else {
					a[i].num[j] = 1;
					a[i].num[j+1] = 1;
					Sx = a[i].x[j];
					Sy = a[i].x[j+1];	
				}
			}		
		}
	}	
	
	
	
			
			
	cout << o << " " << p << endl;
	for(int i = 0;i < n;i++){
		for(int j = 0;j < 2*m;j++){
			if(a[i].num[j] == 2){
				return 0;
			} else if(a[i].num[j] == 1){
				cout << a[i].x[j] << " " << a[i].x[j+1] << endl;
				j = j + 1;
			}
		}
	}
	return 0;
}