while True:
  try:
    def function1(num):
      for i in range(num,0,-1):
        total=0
        I=str(i)
        for a in I:
          if int(a)%2==1:
            total+=1
        if len(I)==total:
          return i
          break

    def function2(x):
      for i in range(x,10000000,1):
        total=0
        I=str(i)
        for a in I:
          if int(a)%2==1:
            total+=1
        if len(I)==total:
          return i
          break
    N=int(input())
    K2=function2(N)-N
    K1=N-function1(N)
    print(min(K1,K2))
  except EOFError:
    break