#include <bits/stdc++.h>
using namespace std;
int match[110], chw[110], tsp;
vector<int> G[110];
bool findmuniu(int x)
{
    for(int y : G[x])
    {
        if(chw[y] != tsp)
        {
            chw[y] = tsp;
            if(match[y] == 0 || findmuniu(match[y]) == 1)
            {
                match[y] = x;
                return 1;
            }
        }
    }
    return 0;
}
struct node{double x, y;}A[110], B[110];
double dis(node n1, node n2){return sqrt( (n1.x - n2.x)*(n1.x - n2.x) + (n1.y - n2.y)*(n1.y - n2.y) );}
int main()
{
    int n, m; double s, v;
    while(scanf("%d%d%lf%lf", &n, &m, &s, &v) != EOF)
    {
        for(int i = 1; i <= n; i++) scanf("%lf%lf", &A[i].x, &A[i].y);
        for(int i = 1; i <= m; i++) scanf("%lf%lf", &B[i].x, &B[i].y);
        memset(G, 0, sizeof(G));
        for(int i = 1; i <= n; i++)
            for(int j = 1; j <= m; j++)
                if(dis(A[i], B[j]) <= s * v)
                    G[i].emplace_back(j);
        int ans = 0;
        memset(match, 0, sizeof(match));
        memset(chw, 0, sizeof(chw));
        for(int i = 1; i <= n; i++)
        {
            tsp = i;
            if(findmuniu(i) == 1) ans++;
        }
        printf("%d\n", n - ans);
    }
    return 0;
}