/*
    Author:zeke

    pass System Test!
    GET AC!!
*/
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using ll = long long;
using ld = long double;
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define rep3(var, min, max) for (ll(var) = (min); (var) < (max); ++(var))
#define repi3(var, min, max) for (ll(var) = (max)-1; (var) + 1 > (min); --(var))
#define Mp(a, b) make_pair((a), (b))
#define F first
#define S second
#define Icin(s) \
    ll(s);      \
    cin >> (s);
#define Scin(s) \
    ll(s);      \
    cin >> (s);
template <class T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T& a, const T& b) {
    if (b < a) {
        a = b;
        return 1;
    }
    return 0;
}
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef vector<V> VV;
typedef vector<P> VP;
ll mod = 1e9 + 7;
ll MOD = 1e9 + 7;
ll INF = 1e18;
// cout << "Case #" << index << " :IMPOSSIBLE";
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    ll n,m;
    cin>>n>>m;
    V vol(n),res(m);
    rep(i,n)cin>>res[i];
    rep(i,m)cin>>vol[i];
    ll a,b;
    cin>>a>>b;
    V dp(1e6+100,0);
    dp[0]=1;
    rep(i,n){
        for(int j=1e6;j>=0;j--){
            if(j+res[i]>1e6)continue;
            dp[j+res[i]]+=dp[j];
            dp[j+res[i]]%=MOD;
        }
    }
    rep3(i,1,1e6+100){
        dp[i]+=dp[i-1];
    }
    V dp2(1e6+1,0);
    dp2[0]=1;
    rep(i,m){
        for(int j=1e6;j>=0;j--){
            if(j+vol[i]>1e6)continue;
            dp2[j+vol[i]]+=dp2[j];
            dp2[j+vol[i]]%=MOD;
        }
    }
    
    
    ll r=0;
    //cout<<"hello"<<endl;
    rep3(i,1,1e6+1){
        ll k=dp2[i];
        ll g=dp[min(max(0LL,i*a-1),(ll)1e6)];
        ll h=dp[min(i*b,(ll)1e6)];
      //  cout<<i<<" "<<k<<" "<<g<<" "<<h<<endl;
        r+=k*(h+MOD-g);
        r%=MOD;
    }
    cout<<r<<endl;
}