input: Write a function to print the Fibonacci series up to a given number. If the number is less than 0, print "Incorrect input".
  
  def fibonacci(n): 
      a = 0
      b = 1
      if n < 0: 
          print("Incorrect input") 
      elif n == 0: 
          print(a) 
      elif n == 1: 
          print(b) 
      else: 
          print(a, end=" ")
          print(b, end=" ")
          for i in range(2, n): 
              c = a + b 
              a = b 
              b = c 
              print(c, end=" ")
  
  n = int(input("Enter a number: "))
  fibonacci(n)
  
  assert fibonacci(5) == None
  assert fibonacci(-1) == None
  assert fibonacci(0) == None
  assert fibonacci(1) == None
output: def fibonacci(n): 
      a = 0
      b = 1
      if n < 0: 
          print("Incorrect input") 
      elif n == 0: 
          print(a) 
      elif n == 1: 
          print(b) 
      else: 
          print(a, end=" ")
          print(b, end=" ")
          for i in range(2, n): 
              c = a + b 
              a = b 
              b = c 
              print(c, end=" ")