#include <iostream>
#include <fstream>
#include <vector>
#include <map>

using namespace std;

ifstream fin("ograzi.in");
ofstream fout("ograzi.out");

const int NMAX = 1e5;

int n, m, w, h;

map <pair <int, int>, vector <pair <int, int>>> mp;

struct Rect{
    int x1, y1;
    int x2, y2;
}rects[NMAX + 1];

bool inside(pair <int, int> p, Rect rect){
    return (rect.x1 <= p.first && p.first <= rect.x2 && rect.y2 <= p.second && p.second <= rect.y1);
}

int main(){

    fin >> n >> m >> w >> h;

    for(int i = 1; i <= n; i++){
        fin >> rects[i].x1 >> rects[i].y2;
        rects[i].y1 = rects[i].y2 + h;
        rects[i].x2 = rects[i].x1 + w;
    }

    for(int i = 1; i <= m; i++){
        int x, y;
        fin >> x >> y;

        mp[{x / w, y / h}].push_back({x, y});
    }   

    int ans = 0;

    for(int i = 1; i <= n; i++){
        pair <int, int> quadrant1 = {rects[i].x1 / w, rects[i].y1 / h};
        pair <int, int> quadrant2 = {rects[i].x2 / w, rects[i].y1 / h};
        pair <int, int> quadrant3 = {rects[i].x2 / w, rects[i].y2 / h};
        pair <int, int> quadrant4 = {rects[i].x1 / w, rects[i].y2 / h};

        for(auto p : mp[quadrant1]){
            if(inside(p, rects[i]))
                ans++;
        }

        for(auto p : mp[quadrant2]){
            if(inside(p, rects[i]))
                ans++;
        }

        for(auto p : mp[quadrant3]){
            if(inside(p, rects[i]))
                ans++;
        }

        for(auto p : mp[quadrant4]){
            if(inside(p, rects[i]))
                ans++;
        }
    }

    fout << ans << '\n';

    return 0;
}