input: Write a function named fibonacci that generates the nth Fibonacci number using a recursive approach. If n is 1 or 2, the function should return 1. Otherwise, the function should return the sum of the two preceding Fibonacci numbers (i.e., fibonacci(n-1) + fibonacci(n-2)).
  assert fibonacci(10) == 55
  assert fibonacci(1) == 1
  assert fibonacci(2) == 1
  assert fibonacci(5) == 5
  assert fibonacci(7) == 13
output: def fibonacci(n):
      if n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n-1) + fibonacci(n-2)