UVA1471 防线 Defense Lines

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=447&page=show_problem&problem=4217 [PDF](https://uva.onlinejudge.org/external/14/p1471.pdf)

Input Format

N/A

Output Format

N/A