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: [12, 42, 19, 39, 30, 16, 48, 7, 4, 47, 43, 18, 6, 11, 21, 20, 32, 22, 25, 5], target=39

[21, 18]