#include <iostream>
#include <string>
using namespace std;


int main(){
	int m,n,Sx,Sy,count=0;
	char c;
	cin >> m >> n >>Sx>>Sy;
	int s[m*n+10][2];
	for(int i=0;i<n;i++){
		do{
			cin >> s[count][0] >>s[count][1];
			count++;
		}while( (c=getchar()) ==' ' );
	}
	cout<<Sx<<" "<<Sy<<endl;
	for(int i=0;i<count;i++){
		if(s[i][0]==0&&s[i][1]==0)
			return 0;
		cout<<s[i][0]<<" "<<s[i][1]<<endl;
	}
	
	return 0;
}