#include <iostream>
#include <vector>
using namespace std;
using ll = long long int;
constexpr ll MOD = 1'000'000'007;

int main(){
    int n, m;
    cin >> n >> m;
    vector<ll> v(n), r(m);
    for(auto &p: v) cin >> p;
    for(auto &p: r) cin >> p;
    int a, b;
    cin >> a >> b;

    const int cntlim = 100010;
    vector<ll> vcnt(cntlim, 0), rcnt(cntlim, 0);
    vcnt[0] = rcnt[0] = 1;
    for(auto &p: v){
        for(int i = cntlim-1; i >= 0; i--){
            if(vcnt[i] > 0) vcnt[i+p] += vcnt[i];
        }
    }
    for(auto &p: r){
        for(int i = cntlim-1; i >= 0; i--){
            if(rcnt[i] > 0) rcnt[i+p] += rcnt[i];
        }
    }
    for(int i = 1; i < cntlim; i++) rcnt[i] += rcnt[i-1];
    //for(int i = 0; i < 20; i++) cerr << vcnt[i] << " ";
    ll ans = 0;
    for(int v1 = 1; v1 < cntlim; v1++){
        int r1 = v1/a;
        int r2 = (v1+b-1)/b;
        if(r1 < r2) continue;
        //cerr << r1 << " " << r2 << endl;
        ans += vcnt[v1]*(rcnt[r1]-rcnt[r2-1]);
        ans %= MOD;
    }
    cout << ans << endl;
    return 0;
}