The first and second numbers in the Fibonacci sequence are both 1. After that, each subsequent number is the sum of the two preceding numbers. The first several numbers in the sequence are: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, etc. Write function named fib that takes a positive integer parameter and returns the number at that position of the Fibonacci sequence. For example fib(1) = 1, fib(3) = 2, fib(10) = 55, etc. Your function does not need to print anything out - just return a value.