#include <iostream>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <bits/stdc++.h>

using namespace std;

bool sortbysec(const pair<string,int> &a, const pair<string,int> &b)
{
    return (a.second < b.second);
}

int main()
{
    int m, w, n, r;
    cin >> m;
    int mw[m];
    for (int i=0; i<m; i++){
        cin >> mw[i];
    }
    cin >> w;
    int ww[w];
    for (int i=0; i<w; i++){
        cin >> ww[i];
    }
    cin >> r >> n;
    pair<string, int> kay[w];
    //memset(kay, 0, w*4);
    for (int i=0; i<w; i++){
        kay[i].second = 0;
        for (int j=0; j<m; j++){
            if (abs(ww[i] - mw[j]) <= r){
                kay[i].first[j] = '1';
                kay[i].second++;
            }
            else{
                kay[i].first[j] = '0';
            }
        }
    }
    sort(kay, kay+n, sortbysec);
    reverse(kay, kay+n);
    for (int i=1; i<w; i++){
        int b = 0;
        if (kay[i-1].second != kay[i].second){
            sort(kay+b, kay+(i-1));
            reverse(kay+b, kay+(i-1));
            b = i;
        }
    }
    for (int i=1; i<w; i++){
        int b = 0;
        if (kay[i-1].first != kay[i].first){
            if ((i-1)-b >= n){
                cout << endl << kay[i-1].second;
                return 0;
            }
            b = i;
        }
    }
    cout << endl << -1;
    return 0;
}