Definition: You are given a list of integers and an integer target, return a list of a pair of numbers in any order such that they add up to target. If there is no such pair of numbers, then return an empty list
Input: [8, 37, 11, 21, 18, 13, 7, 40, 29, 17, 2, 15, 39, 34, 27, 42, 16, 47, 33, 23], target=31

[23, 8]