# xiaoyu

## 2019 ICPC国际大学生程序设计竞赛中国邀请赛（南昌） H. Coloring Game

David has a white board with 2 \times N2×N grids.He decides to paint some grids black with his brush.He always starts at the top left corner and ends at the bottom right corner, where grids should be black ultimately.