MOD = 10 ** 9 + 7

n, m = map(int, input().split())
V = list(map(int, input().split()))
R = list(map(int, input().split()))
a, b = map(int, input().split())

W = sum(V)
dp = [0] * (W + 1)
dp[0] = 1
for v in V:
    for i in range(W, v - 1, -1):
        dp[i] += dp[i - v]
        dp[i] %= MOD
        
for i in range(1, W + 1):
    dp[i] += dp[i - 1]
    dp[i] %= MOD

W2 = sum(R)
dp2 = [0] * (W2 + 1)
dp2[0] = 1
for r in R:
    for i in range(W2, r - 1, -1):
        dp2[i] += dp2[i - r]
        dp2[i] %= MOD
        
ans = 0
for i in range(1, W2 + 1):
    mi = a * i - 1
    if mi >= W:
        break
    ma = min(b * i, W)
    ans += dp2[i] * (dp[ma] - dp[mi])
    ans %= MOD
print(ans)