input: Write a function to generate Fibonacci numbers recursively. The function should take an integer `n` as input and return the nth Fibonacci number. If `n` is 1 or 2, the function should return 1. For other values of `n`, the function should return the sum of the (n-1)th and (n-2)th Fibonacci numbers.
  
  def fibonacci(n):
      if n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)
  
  assert fibonacci(10) == 55
  assert fibonacci(1) == 1
  assert fibonacci(2) == 1
  assert fibonacci(5) == 5
  assert fibonacci(15) == 610
output: def fibonacci(n):
      if n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)