input: Write a function to calculate the nth term of the Fibonacci sequence recursively. If the input is 0, return 0. If the input is 1, return 1. For any other input, return the sum of the two preceding terms.
  
  assert fibonacci_seq(0)==0
  assert fibonacci_seq(1)==1
  assert fibonacci_seq(2)==1
  assert fibonacci_seq(3)==2
  assert fibonacci_seq(4)==3
  assert fibonacci_seq(5)==5
output: def fibonacci_seq(n):
      if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return fibonacci_seq(n-1) + fibonacci_seq(n-2)