UVA12823 Four coloring of a map

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=861&page=show_problem&problem=4688 [PDF](https://uva.onlinejudge.org/external/128/p12823.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12823/dbd06d68f77a9fe66ab7e5ffcd1bc2de6ba8d1e2.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12823/35d7b3f005d1ac8e128c5002e6e71a741ae58865.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12823/512420791e2a620478563237841cf5de31d7c003.png)