x,y,k,p = map(int,input().split())
left = x+y-k
if left & 1:
  if x <= left//2:
    yy = y - (k-x)
    tmp = pow(-1, yy)
    if tmp == p:
      print("Alice")
    else:
      print("Bob")
  elif y <= left//2:
    tmp = 1
    if tmp == p:
      print("Alice")
    else:
      print("Bob")
  else:
    print("Alice")
else:
  if x <= left//2:
    yy = y - (k-x)
    tmp = pow(-1, yy)
    if tmp == p:
      print("Alice")
    else:
      print("Bob")
  elif y <= left//2:
    tmp = 1
    if tmp == p:
      print("Alice")
    else:
      print("Bob")
  else:
    print("Bob")