#include <bits/stdc++.h>
using namespace std;
#define SZ(x) (int)(x.size())
#define REP(i, n) for(int i=0;i<(n);++i)
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define RREP(i, n) for(int i=(int)(n)-1;i>=0;--i)
#define RFOR(i, a, b) for(int i=(int)(b)-1;i>=(a);--i)
#define ALL(a) a.begin(),a.end()
#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using P = pair<int, int>;
const double EPS = 1e-8;
const ll MOD = 1000000007;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;
template <typename T1, typename T2>
bool chmax(T1 &a, const T2 &b) {
    if (a < b) { a = b; return true; }
    return false;
}
template <typename T1, typename T2>
bool chmin(T1 &a, const T2 &b) {
    if (a > b) { a = b; return true; }
    return false;
}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp);
template<typename T>
ostream &operator<<(ostream &os, const vector<T> &v);

template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
    os << "(" << p.first << ":" << p.second << ")";
    return os;
}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
    os << "{";
    int a = 0;
    for (auto &tp : mp) {
        if (a) os << ", "; a = 1;
        os << tp;
    }
    return os << "}";
}
template<typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "[";
    REP(i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    int n, m; cin >> n >> m;
    vi V(n), R(m);
    REP(i, n) cin >> V[i];
    REP(i, m) cin >> R[i];
    int A, B; cin >> A >> B;

    int sumV = accumulate(ALL(V), 0);

    vll dpv(sumV+1);
    dpv[0] = 1;
    REP(i, n) {
        RREP(v, sumV) {
            if (v + V[i] <= sumV) (dpv[v + V[i]] += dpv[v]) %= MOD;
        }
    }

    int sumR = accumulate(ALL(R), 0);

    vll dpr(sumR+1);
    dpr[0] = 1;
    REP(i, m) {
        RREP(r, sumR) {
            if (r + R[i] <= sumR) (dpr[r + R[i]] += dpr[r]) %= MOD;
        }
    }

    vll sum(sumR+2);
    REP(i, sumR+1) {
        sum[i+1] = sum[i] + dpr[i];
    }

    ll ans = 0;
    REP(v, sumV+1) {
        if (dpv[v] == 0) continue;
        ll l = max((v - 1 + B) / B, 0), r = min(v / A, sumR);
        if (l > r) continue;
        ll sr = (sum[r+1] - sum[l] + MOD) % MOD;
        (ans += dpv[v] * sr) %= MOD;
    }
    if (ans > 0) --ans;
    else ans = MOD-1;
    cout << ans << endl;

    return 0;
}