input: 
  def fibonacci(n: int) -> None:
      """ Print Fibonacci series up to a given number n.
      Example:
      >>> fibonacci(10)
      0 1 1 2 3 5 8 13 21 34
      """
      a, b = 0, 1
      while a <= n:
          print(a, end=' ')
          a, b = b, a + b
  
  # Example usage:
  n = int(input("Enter a number: "))
  fibonacci(n)
  
output:     a, b = 0, 1
      while a <= n:
          print(a, end=' ')
          a, b = b, a + b