#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);
const long long MOD = 1000000007;

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

  int n, m;
  cin >> n >> m;
  vector<int> v(n), r(m);

  REP (i, n) cin >> v[i];
  REP (i, m) cin >> r[i];

  int a, b;
  cin >> a >> b;
  
  // v pattern
  vector<long long> pv(100000 + 1);
  pv[0] = 1;
  REP (i, n) for (int j = pv.size() - 1; j >= 0; j--) if (j >= v[i]) (pv[j] += pv[j-v[i]]) %= MOD;
  
  // r pattern
  vector<long long> pr(100000 + 1);
  pr[0] = 1;
  REP (i, m) for (int j = pr.size() - 1; j >= 0; j--) if (j >= r[i]) (pr[j] += pr[j-r[i]]) %= MOD;
  for (int i = 1; i < pr.size(); i++) (pr[i] += pr[i-1]) %= MOD;
  
  long long ret = 0;
  for (int i = 1; i < pv.size(); i++) {
    long long x = pv[i];
    int rmin = (i + b - 1) / b;
    int rmax = i / a;
    long long y = pr[rmax] - pr[rmin-1];
    y %= MOD;
    if (y < 0) y += MOD;
    (ret += x * y % MOD) %= MOD;
  }

  cout << ret << endl;
  
  return 0;
}