#include <bits/stdc++.h>
#define rep(i,n) for(int i=(0);i<(n);i++)

using namespace std;

typedef long long ll;

ll ceil(ll a, ll b){
	return (a + b - 1) / b;
}

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	ll MOD = 1e9 + 7;

	ll n, m;
	cin >> n >> m;

	vector<ll> v(n), r(m);
	rep(i, n) cin >> v[i];
	rep(i, m) cin >> r[i];

	ll a, b;
	cin >> a >> b;

	int max_n = 101010;

	ll dpv[2][max_n];
	rep(i, 2) rep(j, max_n) dpv[i][j] = 0;
	dpv[0][0] = 1;

	rep(i, n) {
		rep(j, max_n) dpv[(i+1)%2][j] = 0;
		rep(j, max_n){
			dpv[(i+1)%2][j] += dpv[i%2][j];
			dpv[(i+1)%2][j] %= MOD;
			if(j + v[i] < max_n){
				dpv[(i+1)%2][j+v[i]] += dpv[i%2][j];
				dpv[(i+1)%2][j+v[i]] %= MOD;
			}
		} 
	}

	ll dpr[2][max_n];
	rep(i, 2) rep(j, max_n) dpr[i][j] = 0;
	dpr[0][0] = 1;

	rep(i, n) {
		rep(j, max_n) dpr[(i+1)%2][j] = 0;
		rep(j, max_n){
			dpr[(i+1)%2][j] += dpr[i%2][j];
			dpr[(i+1)%2][j] %= MOD;
			if(j + r[i] < max_n){
				dpr[(i+1)%2][j+r[i]] += dpr[i%2][j];
				dpr[(i+1)%2][j+r[i]] %= MOD;
			} 
		}
	}

	vector<ll> sr(max_n+1, 0);
	sr[1] = dpr[m%2][1];
	for(int i = 1; i < max_n; i++) {
		sr[i+1] = sr[i] + dpr[m%2][i+1];
		sr[i+1] %= MOD;
	}

	ll ans = 0;
	for(int i = 1; i < max_n; i++){
		if(ceil((ll)i, b) - 1 < 0) continue;
		ll num = sr[i / a] + MOD - sr[ceil((ll)i, b) - 1];
		num %= MOD;
		ans += dpv[n%2][i] * num;
		ans %= MOD;
	}

	cout << ans << endl;
}