input: Write a python function to implement the fizz buzz game.
  assert fizz_buzz(5) == "1 2 fizz 4 buzz "
  assert fizz_buzz(3) == "1 2 fizz "
  assert fizz_buzz(10) == "1 2 fizz 4 buzz fizz 7 8 fizz buzz "
output: def fizz_buzz(n):
      result = []
      for i in range(1, n + 1):
          if i % 3 == 0 and i % 5 == 0:
              result.append("fizzbuzz")
          elif i % 3 == 0:
              result.append("fizz")
          elif i % 5 == 0:
              result.append("buzz")
          else:
              result.append(str(i))
      return " ".join(result) + " "