UVA11570 Sudoku without numbers?

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=27&page=show_problem&problem=2617 [PDF](https://uva.onlinejudge.org/external/115/p11570.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11570/8a85a12a1408fe9abecd1c5cc2b57f380cd5e0a1.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11570/af0f75bff1b0e2fc48f788b017e57ec1960a9e93.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11570/5f07ba23a39e99c9b98ddcce1d7cb3dc5ce0a4fc.png)