text: from math import fabs
  aux=2
  while True:
      x1,y1,x2,y2=map(int,input().split())
      if x1==y1==x2==y2==0:break
      if x1==x2 and y1==y2:print(0)
      elif((x2-x1) == -(y2-y1) or -(x2-x1) == -(y2-y1) or -(x2-x1) == (y2-y1) or (x2-x1) == (y2-y1)):print("1")
      elif x1==x2 or y1==y2:print(1)
      else:print(2)
  