text: def print_bit(arr):
      for i in arr :
          print(i,end=' ')
      print()
  
  def gen_bit(n,arr,i):
      if n == i :
          print_bit(arr)
          return 
  
      arr[i] = 0 
      gen_bit(n,arr,i+1)
   
      arr[i] = 1 
      gen_bit(n,arr,i+1) 
  
  t = int(input("input:"))
  arr = []
  
  for i in range(t):
      arr.append(0)
  
  print("output:")
  gen_bit(t,arr,0)