import sys
import numpy as np

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

MOD = 10**9 + 7
U = 10**5

N, M = map(int, readline().split())
V = np.array(readline().split(), np.int64)
R = np.array(readline().split(), np.int64)
A, B = map(int, read().split())

def compute_sums(A):
    dp = np.zeros(U + 1, np.int64)
    dp[0] = 1
    for x in A:
        dp[x:] += dp[:-x]
        dp %= MOD
    dp[0] = 0
    return dp

V = compute_sums(V)
R = compute_sums(R)
Vcum = np.cumsum(V) % MOD

i = np.arange(U + 1, dtype=np.int64)
ind1 = np.minimum(U, i * B)
ind2 = np.minimum(U, i * A - 1)
x = (Vcum[ind1] - Vcum[ind2]) * R % MOD
print(x.sum() % MOD)