I can't get ACCEPTED about a half of the year. I think my
algorithm is absolutly right, because I can prove it.

And, some questions to administarion:
1. Can a line break be in the end of output ?
2. Maybe, the C++ operator "cin >>"  doesn't work right in
your environment ?
3. Are you sure that your test data is correct ?

Thanks.

Simple bigraph match will pass it.
But I've got the same problem when using cin... It will run
forever and finally get a TLE.

Sorry, the first line is wrong.
I've solved the problem. I think that's easy.