input: Write a function to generate the nth Fibonacci number using a recursive approach. The Fibonacci sequence is defined such that each number is the sum of the two preceding ones, starting from 0 and 1. The function should return 1 for the first two numbers in the sequence (n=1 and n=2) and recursively compute the nth number for n greater than 2.
  
  def fibonacci(n):
      if n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)
  
  assert fibonacci(1) == 1
  assert fibonacci(2) == 1
  assert fibonacci(10) == 55
  assert fibonacci(13) == 233
  assert fibonacci(20) == 6765
output: def fibonacci(n):
      if n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)