def input_int():
    return int(input())

def input_ints():
    return list(map(int, input().split()))

import numpy as np

MOD = 10**9 + 7

N, M = input_ints()
V = input_ints()
R = input_ints()
A, B = input_ints()

dp = np.zeros(10**5 + 10, dtype=np.int64)
dp[0] = 1
for i in range(N):
    dp[V[i]:] += dp[:-V[i]]
    dp %= MOD

ep = np.zeros(10**5 + 10, dtype=np.int64)
ep[0] = 1
for i in range(M):
    ep[R[i]:] += ep[:-R[i]]
    ep %= MOD
ep[0] = 0
ep = np.cumsum(ep)
ep %= MOD

ans = 0
for i in range(len(dp)):
    # i/B <= j <= i/A
    ans += dp[i] * ep[i // A]
    if i > 0:
        ans -= dp[i] * ep[(i + B - 1) // B - 1]
print(ans % MOD)