input: Write a function to recursively generate the Fibonacci sequence up to the nth term. The function should return the nth Fibonacci number. If the input is less than or equal to 0, the function should return 0. If the input is 1 or 2, the function should return 1.
  def fibonacci(n):
      if n <= 0:
          return 0
      elif 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(0)==0
  assert fibonacci(-1)==0
output: def fibonacci(n):
      if n <= 0:
          return 0
      elif n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)