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
Q: [12, 21, 30, 29, 45, 15, 36, 16, 13, 39, 37, 6, 31, 24, 17, 14, 33, 27, 8, 4], target=34
A: 
[21, 13]