UVA961 Ambiguous or Incomplete Inductive Definitions

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=11&page=show_problem&problem=902 [PDF](https://uva.onlinejudge.org/external/9/p961.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA961/c99b5de2a384b18fdb9c827c53f30d37d03196f6.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA961/d5bbf81c5dbc2867634d7a9e2b14f6fa3b06e71b.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA961/908e8b18c1289af0aed4bc8f6c3c8e454a7bf948.png)