input: Write a function to generate and display a Fibonacci sequence of the first n numbers. The function should return the Fibonacci number for the given index. If n is 1, return 0. If n is 2, return 1. For any other value of n, return the sum of the two preceding Fibonacci numbers.
  def Fibonacci(n):
      if n==1:
          return 0
      elif n==2:
          return 1
      else:
          return Fibonacci(n-1)+Fibonacci(n-2)
  
  assert Fibonacci(1)==0
  assert Fibonacci(2)==1
  assert Fibonacci(5)==3
  assert Fibonacci(10)==34
output: def Fibonacci(n):
      if n==1:
          return 0
      elif n==2:
          return 1
      else:
          return Fibonacci(n-1)+Fibonacci(n-2)