Write a Python program named fibonacci.py to solve programming exercise #16 from Chapter 3: A Fibonacci number is a sequence of numbers where each successive number is the sum of the previous two. The classic Fibonacci sequence begins: 1, 1, 2, 3, 5, 8, 13, . Write a program that computes the nth Fibonacci number where n is a value input by the user. For example, if n = 6, then the result is 8.