#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
constexpr int INF = 1e9;
constexpr long long LINF = 1e18;
constexpr int MOD = 1000000007;
const int MX = 100005;

vector<ll>  count(ll n,const vector<ll>& a){
    vector<vector<ll>> dp(n+1,vector<ll>(MX,0));
    dp[0][0] = 1;
    for(int i=1;i<=n;i++){
        rep(j,MX){
            if(j - a[i-1] >= 0){
                dp[i][j] = (dp[i-1][j] + dp[i-1][j-a[i-1]])%MOD;
            }else{
                dp[i][j] = dp[i-1][j];
            }
        }
    }
    dp[n][0] = 0;
    return dp[n];
}

ll under(ll A,vector<ll> v,vector<ll> r){
    ll ans = 0;
    rep(i,MX){
        if(A*i >= MX) ans = (ans + (v[MX-1]*r[i])%MOD)%MOD;
        else ans = (ans + (v[A*i]*r[i])%MOD)%MOD;
    }
    return ans;
}

ll just(ll A,vector<ll> v,vector<ll> r){
    ll ans = 0;
    rep(i,MX){
        if(A*i >= MX);
        else ans = (ans + (v[A*i]*r[i])%MOD)%MOD;
    }
    return ans;
}

int main(){
    ll n,m;
    cin >> n >> m;
    vector<ll> v(n);
    rep(i,n) cin >> v[i];
    vector<ll> r(m);
    rep(i,m) cin >> r[i];
    ll a,b;
    cin >> a >> b;
    vector<ll> V = count(n,v);
    vector<ll> R = count(m,r);
    ll C = just(a,V,R);
    /*
    rep(i,100) cout << V[i] <<" ";
    cout << endl;
    rep(i,100) cout << R[i] <<" ";
    cout << endl;
    */
    rep(i,MX-1) V[i+1] = (V[i+1] + V[i])%MOD;
    ll A = under(a,V,R);
    ll B = under(b,V,R);
    //cout << A << " "<< B << endl;
    cout << (B - A + C + MOD)%MOD << endl;
    return 0;
}