In order to get better results in official ACM/ICPC contests, the team leader comes up with a questionnaire. He asked everyone in the team whether to have more training.
Picture from Wikimedia Commons
Obviously many people don't want more training, so the clever leader didn't write down their words such as ''Yes'' or ''No''. Instead, he let everyone choose a positive integer $a_i$ to represent his opinion. When finished, the leader will choose a pair of positive interges $m(m>1)$ and $k(0\leq k<m)$, and regard those people whose number is exactly $k$ modulo $m$ as ''Yes'', while others as ''No''. If the number of ''Yes'' is not less than ''No'', the leader can have chance to offer more training.
Please help the team leader to find such pair of $m$ and $k$.