#include<stdio.h>
long n,m,w,h,a[2000000][2000000];
int main()
{      	long i,j,k,x,y,nr=0;
	FILE *f=fopen("ograzi.in","r"),*g=fopen("ograzi.out","w");
	fscanf(f,"%ld %ld %ld %ld",&n,&m,&w,&h);
	for(i=1;i<=n;i++)
	{
		fscanf(f,"%ld %ld",&x,&y);
		for(j=y;j<=y+h;j++)
			for(k=x;k<=x+w;k++)
				a[k][j]=1;
	}
	for(i=1;i<=m;i++)
	{
		fscanf(f,"%ld %ld",&x,&y);
		if(a[x][y])
			nr++;
	}
	fclose(f);
	fprintf(g,"%ld",nr);
	fclose(g);
	return 0;
}