input: Write a recursive Python function to generate Fibonacci numbers. The function should return the nth Fibonacci number. If n is 1 or 2, the function should return 1. Otherwise, it should recursively 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
output: def fibonacci(n):
      if n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)