I have no idea where to start with this problem. I've been stuck on it for awhile any guidance would be appreciated.
$A = [2,5,8,11,14,17,20,23,26,29,32,35]$
This sets consists of all numbers in the form 3k+2 which are less than or equal to 35. What is the smallest number n that has the following property: if we choose n numbers from A randomly, then there will always be a pair of numbers that sum to 37.