x,y,k,p = map(int,input().split())
at = (x+y-k+1)//2
bt = x+y-k-at
if p == 1:
  if at > bt:
    print("Alice")
  else:
    if y > at:
      print("Bob")
    else:
      print("Alice")
else:
  if at == bt:
    print("Bob")
  else:
    if y > bt:
      print("Alice")
    else:
      print("Bob")