input: 
  
  def string_sequence(n: int) -> str:
      """ Return a string containing space-delimited numbers starting from 0 upto n inclusive.
      >>> string_sequence(0)
      '0'
      >>> string_sequence(5)
      '0 1 2 3 4 5'
      """
  
output:     result = []
      for i in range(n + 1):
          result.append(str(i))
      return ' '.join(result)