Hey Codeforces! I'm exicited to invite you to The 4th Universal Cup, Stage 23, the Grand Prix of Nanyang, taking place on May 2nd, 2026.

The contest is based on the Finals of the CCPC (China Collegiate Programming Contest), which was held on April 26, 2026. This is my fourth time create the problem-set and serve as a judge for the CCPC Finals.

This contest is prepared by EvenImage, Qingyu, RDDCCD, and Kevin114514, with the help of our outstanding judge team Gellyfish, zhoukangyang, ODT, Coffee_zzz, unputdownable.

Although the style of problems differs a bit, the difficulty of this problem set is close to the last (the 2nd) Universal Cup Finals. We believe the problems will be engaging for all Div. 1 participants, while still providing a challenge for the strongest teams.

We are looking forward to your participation!