给组样例，可以自己拍一下：
```
4 5 1
1 3 1 3
2 1 2 2 1
2 3 3 5
```
输出应该是 3
by thostever @ 2022-10-31 14:05:53
自己调出来收获更大！
by cjwdxfblzs @ 2022-11-01 19:25:57
@[OPTIM](/user/232067) 草
by _GrainRain_ @ 2022-11-01 22:52:02