#include<bits/stdc++.h>
using namespace std;
int n,s;
int a,b;
struct uc{
	int x,y;
}ss[5001];
bool cmp(uc x,uc y){
	return x.y<y.y;
}
int main(){
	cin>>n>>s;
	cin>>a>>b;
	int rn=0;
	for(int i=1;i<=n;i++){
		int x,y;
		cin>>x>>y;
		if(x<a+b||x==0) ss[rn++].x=x,ss[rn].y=y;
	}
	sort(ss+1,ss+1+rn,cmp);
	int ans=0;
	cout<<endl;
	for(int i=1;i<=rn;i++){
		s-=ss[i].y;
		if(s>=0) ans++,cout<<ss[i].x<<" "<<ss[i].y<<endl;
	}
	cout<<ans;
	return 0;
}