#include<bits/stdc++.h>
using namespace std;
class InParser {
private:
	FILE *fin;
	char *buff;
	int sp;

	char read_ch() {
		++sp;
		if (sp == 4096) {
			sp = 0;
			fread(buff, 1, 4096, fin);
		}
		return buff[sp];
	}

public:
	InParser(const char* nume) {
		fin = fopen(nume, "r");
		buff = new char[4096]();
		sp = 4095;
	}

	InParser& operator >> (int &n) {
		char c;
		while (!isdigit(c = read_ch()) && c != '-');
		int sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}

	InParser& operator >> (long long &n) {
		char c;
		n = 0;
		while (!isdigit(c = read_ch()) && c != '-');
		long long sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}
}f("ograzi.in");
ofstream g("ograzi.out");
int n, m, w, h;
struct puncte
{
    int x, y;
};
puncte rect[50002], points[100002];
bool cmp(puncte a, puncte b)
{
    if(a.x == b.x)
        return a.y < b.y;
    return a.x < b.x;
}
int st, dr, b;
int ans = 0;
multiset<int>ms;
multiset<int> ::iterator it;
int sm(puncte a, puncte b)
{
    if(a.x < b.x)
        return 1;
    if(a.x > b.x)
        return 2;
    if(a.y <= b.y)
        return 1;
    return 2;
}
int main()
{
    f >> n >> m >> w >> h;
    for(int i = 1; i <= n; ++i)
        f >> rect[i].x >> rect[i].y;
    for(int i = 1; i <= m; ++i)
        f >> points[i].x >> points[i].y;
    sort(rect + 1, rect + n + 1, cmp);
    sort(points + 1, points + m + 1, cmp);
    rect[n+1] = {1000000000, 1000000000};
    points[m+1] = {1000000000, 1000000000};
    st = 1, dr = 1, b = 1;
    while(b <= m)
    {
        int rez = sm(rect[dr], points[b]);
        puncte x;
        if(rez == 1)
            x = rect[dr];
        else
            x = points[b];
        while(x.x - rect[st].x > h)
        {
            it = ms.lower_bound(rect[st].y);
            ms.erase(it);
            ++st;
        }
        if(rez == 1)
            ms.insert(rect[dr].y), ++dr;
        else
        {
            if(!ms.empty())
            {
                if(*ms.begin() > x.y);
                else
                {
                    it = ms.upper_bound(x.y);
                    --it;
                    if(x.y - *it <= w)
                        ++ans;
                }
            }
            ++b;
        }
    }
    g << ans;
    return 0;
}