Write a function that takes an integer argument and prints the Fibonacci numbers at that position in the series. Take this opportunity to think about how you can use functions. (Hint: The Fibonacci sequence is a sequence of numbers where the next number in the sequence is the sum of the previous two numbers in the sequence. The sequence looks like this: 1, 1, 2, 3, 5, 8, 13, ...). As a practice, call the function with 20 as the argument and it should give an output similar to the following. Fibonacci number 20 -> 6765