Write a function that outputs the smallest missing number in a sorted array of n unique integers. The integers in the array range from 0 to m-1, where m > n.
The function should be called SmallestMissingNumber and the 3 inputs are: the array, the "start value" of the array (e.g. 0), and the length of the array - 1, or "end value".
Examples:
Input: [0, 1, 3, 4, 8, 9], n = 5, m = 10
Output: 2 Input: [4, 7, 9, 11], n = 4, m = 12
Output: 0 Solution will be written using Python.