import times, strutils, sequtils, math, algorithm, tables, sets, lists, intsets
import critbits, future, strformat, deques
template `max=`(x,y) = x = max(x,y)
template `min=`(x,y) = x = min(x,y)
template `mod=`(x,y) = x = x mod y
template scan2 = (scan(), scan())
template scan3 = (scan(), scan())
let read* = iterator: string {.closure.} =
    while true: (for s in stdin.readLine.split: yield s)
proc scan(): int = read().parseInt
proc scanf(): float = read().parseFloat
proc toInt(c:char): int =
    return int(c) - int('0')



proc solve():int=
  var
    md = 1000000007
    n = scan()
    m = scan()
    v = newseqwith(n,scan())
    r = newseqwith(m,scan())
    vsize = 100*1000#n*v.max()
    rsize = 100*1000#m*r.max()
    a = scan()
    b = scan()

    makev = newseqwith(n+1,newseqwith(vsize+1,0))
    maker = newseqwith(m+1,newseqwith(rsize+1,0))
    cumv = newseqwith(vsize+1,0)
    cumr = newseqwith(rsize+1,0)
  makev[0][0]=1
  maker[0][0]=1
  for i in 1..n:
    var idx = i-1
    for val in 0..vsize:
      if val-v[idx]>=0:
        makev[i][val] = makev[i-1][val] + makev[i-1][val-v[idx]]
      else:
        makev[i][val] = makev[i-1][val]
      makev[i][val].mod=md


  for i in 1..m:
    var idx = i-1
    for val in 0..rsize:
      if val-r[idx]>=0:
        maker[i][val] = maker[i-1][val] + maker[i-1][val-r[idx]]
      else:
        maker[i][val] = maker[i-1][val]
      maker[i][val].mod=md
  for val in 1..vsize:
    cumv[val]=cumv[val-1]+makev[n][val]
    cumv[val]=(cumv[val].mod(md)+md).mod(md)
  cumr[0]=1
  cumv[0]=1
  for val in 1..rsize:
    cumr[val]=cumr[val-1]+maker[n][val]
    cumr[val]=(cumr[val].mod(md)+md).mod(md)

  
  #echo cumr
  for idx in 1..vsize:# vの値で走査
    var
      right = idx.div(a)
      left = (idx+b-1).div(b)
    #echo idx,", ", right, ", ", left
    var t = cumr[min(right,rsize)]-cumr[max(0,min(rsize,left-1))]
    t = (t.mod(md)+md).mod(md)
    result+=makev[n][idx]*t
    result.mod=md




  


  

  
echo solve()