def Subsum_Count(L):
    L_sum=sum(L)
    X=[0]*(L_sum+1)
    X[0]=1

    for x in L:
        for a in range(L_sum,x-1,-1):
            X[a]+=X[a-x]
            X[a]%=Mod
    return X

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

Mod=10**9+7

V_sum=sum(V)
X=Subsum_Count(V)

R_sum=sum(R)
Y=Subsum_Count(R)

X_accum=[0]*len(X)
X_accum[0]=X[0]

for i in range(1,len(X)):
    X_accum[i]=X_accum[i-1]+X[i]
    X_accum[i]%=Mod

Ans=0
for r in range(1,R_sum+1):
    left =max(r*A,0)
    right=min(r*B,V_sum)

    if left>right:
        continue

    if left==0:
        Ans+=Y[r]*X_accum[right]
    else:
        Ans+=Y[r]*(X_accum[right]-X_accum[left-1])
    Ans%=Mod
print(Ans)