import sys
input=lambda: sys.stdin.readline().rstrip()
n,m=map(int,input().split())
V=[int(i) for i in input().split()]
R=[int(i) for i in input().split()]
a,b=map(int,input().split())
v,r=sum(V),sum(R)
VT=[1]+[0]*v
RT=[1]+[0]*r

for i in range(n):
  for j in range(v)[::-1]:
    if j+1>=V[i]:
      VT[j+1]+=VT[j+1-V[i]]
for i in range(m):
  for j in range(r)[::-1]:
    if j+1>=R[i]:
      RT[j+1]+=RT[j+1-R[i]]
VTT=[0]
for i in range(v+1):
  VTT.append(VTT[-1]+VT[i])

mod=10**9+7
ans=0
for i in range(r+1):
  ans+=(VTT[min(v+1,i*b+1)]-VTT[min(v+1,i*a)])*RT[i]
  if ans>mod:
    ans%=mod
print(ans-1)