#include<stdio.h>
#define dim 50002
#define dim1 100002

long int n,m,inaltime,latime;
long int dr[dim],oi[dim1];
long int x[dim],y[dim];
long int OI[dim1];

void citire();
void solve();

int main()
{
    freopen("ograzi.in","r",stdin);
    freopen("ograzi.out","w",stdout);

    citire();
    solve();
    return 0;
}
void citire()
{
     scanf("%d %d %d %d",&n,&m,&latime,&inaltime);
     int i,j;
     for(i=1;i<=n;i++)
	   scanf("%d %d",&x[i],&y[i]);


     for(j=1;j<=m;j++)

		      scanf("%d %d",&oi[j],&OI[j]);


}
void solve()
{
     int i,j,k,poz=0;
     int stjosx,stjosy,stsusx,stsusy,drjosx,drjosy,drsusx,drsusy;
     int nr=0;

     for(i=1;i<=n;i++)
     {
		      stjosx=x[i];
		      stjosy=y[i];
		      drjosx=stjosx+latime;
		      drjosy=stjosy;
		      stsusx=stjosx;
		      stsusy=stjosy+inaltime;
		      drsusx=stsusx+latime;
		      drsusy=stsusy;


			for(j=1;j<=m;j++)
			   if((oi[j]>=stjosx && oi[j]<=drjosx) &&(OI[j]>=stjosy && OI[j]<=stsusy))
			  nr++;



      }


     printf("%d",nr);


}