input: def fibonacci_seq(n: int) -> int:
      """
      Compute the nth number in the Fibonacci sequence.
      >>> fibonacci_seq(0)
      0
      >>> fibonacci_seq(1)
      1
      >>> fibonacci_seq(5)
      5
      >>> fibonacci_seq(10)
      55
      """
      if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return fibonacci_seq(n - 1) + fibonacci_seq(n - 2)
output:     if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return fibonacci_seq(n - 1) + fibonacci_seq(n - 2)