mx = 101010
mod = 10 ** 9 + 7

def f(X):
    n = len(X)
    pre = [0] * mx
    pre[0] = 1
    for i in range(n):
        dp = [0] * mx
        for j in range(mx):
            dp[j] += pre[j]
            if j - X[i] >= 0:
                dp[j] += pre[j - X[i]]
            dp[j] %= mod
        dp, pre = pre, dp
    return pre

N, M = map(int, input().split())
V = list(map(int, input().split()))
R = list(map(int, input().split()))
A, B = map(int, input().split())

V = f(V)
R = f(R)
Vc = [0] * (mx + 1)
for i in range(mx):
    Vc[i + 1] = Vc[i] + V[i]
    Vc[i + 1] %= mod

ans = 0
for i in range(1, mx):
    ans += R[i] * (Vc[min(mx, i * B + 1)] - Vc[min(mx, i * A)])
    ans %= mod

print(ans)