import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        long[] volts = new long[100001];
        volts[0] = 1;
        for (int i = 0; i < n; i++) {
            int x = sc.nextInt();
            for (int j = i * 100; j >= 0; j--) {
                volts[j + x] += volts[j];
                volts[j + x] %= MOD;
            }
        }
        long[] resists = new long[100001];
        resists[0] = 1;
        for (int i = 0; i < m; i++) {
            int x = sc.nextInt();
            for (int j = i * 100; j >= 0; j--) {
                resists[j + x] += resists[j];
                resists[j + x] %= MOD;
            }
        }
        int a = sc.nextInt();
        int b = sc.nextInt();
        for (int i = 1; i <= 100000; i++) {
            volts[i] += volts[i - 1];
            volts[i] %= MOD;
        }
        long ans = 0;
        for (int i = 1; i * a <= 100000; i++) {
            int max;
            if (i * (long)b >= 100000) {
                max = 100000;
            } else {
                max = i * b;
            }
            ans += (volts[max] - volts[i * a - 1] + MOD) % MOD * resists[i] % MOD;
            ans %= MOD;
        }
        System.out.println(ans);
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}