input: Write a function to generate the nth number in the Fibonacci sequence. If n is 0 or 1, return n; otherwise, return the sum of the two preceding numbers in the sequence. The function should be implemented recursively.
  
  def fibonacci_seq(n): 
      if n==0: 
          return 0
      elif n==1: 
          return 1
      else: 
          return fibonacci_seq(n-1)+fibonacci_seq(n-2)
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)