#include<iostream>
#include<algorithm>
using namespace std;
int n,s,a,b,x[5001],y[5001],i,ans;
bool z=false;
int main()
{	
	cin>>n>>s>>a>>b;
	a+=b;
	for(i=1;i<=n;i++)
		cin>>x[i]>>y[i];
	sort(y+1,y+n+1);
	for(i=1;i<=n;i++)
		cout<<endl<<y[i]; 
	for(i=1;i<=n;i++)
	{
		if(a>=x[i])
			z=true;
		if(z==true)
		{
			if(s>=0)
			{
				s-=y[i];
				if(s>=0)
					ans++;
			}
		}
		z=false;
	}
	cout<<ans;
	return 0;
}```