bzoj#P1525. [POI2006]Zos

[POI2006]Zos

Statement

Little Sophie gives a birthday party. She has written a tentative list of her kindergarten friendsshe would like to invite. However, kids are very demanding guests. Mary said she should come, butonly provided Camille and Emily are not present, for they took her doll last week. Little Christopheronly plays with Sophie and Camille and he does not wish to see any other kids at the party. And soon...

Sophie considers a party a success if none of the guests invited has objection against any other'spresence. She has decided not to invite certain kids to assure that the party is a success. On theother hand she would like to invite as many kids as possible. Should Sophie not be able to invite atleast kk kids she won't give any party at all.

Help little Sophie! Write a programme which:

  • reads the number of all Sophie's acquaintances nn, the number kk and a description of kids' demands from the standard input,

  • verifies if it is possible to invite at least kk kids so that the party could be a success,

  • if it is not possible, writes the word NIE (i.e. no in Polish) to the standard output; if it is possible, finds the largest group of kids who could be invited to the party so that it is a success and writes it to the standard output.

Input Format

The first line of the standard input contains two positive integers separated by a single space:

nn - the number of all Sophie's acquaintances (2n1052 \le n \le 10^5) and kk -the minimal number of kids Sophie wishes to invite to the party (n10k<nn-10 \le k < n). The kids are assigned numbers from therange 11 to nn.

The following lines contain a description of kids' demands. In the second line there is a singleinteger mm, 1m3×1061 \le m \le 3\times 10^6

Each of the following mm lines contains a pair of integers aa, bb, separated by a single space (1a,b,n,ab1 \le a,b, \le n, a \neq b). You can assume that each (ordered) pair appears in the standard input once at the most. The pair aa, bb denotes that the child aa does not wish to meet child bb at the party.

Output Format

If it is not possible to invite kk kids to the party so that it is a success then the first and only line ofthe standard output should contain a single word: NIE.

If it is possible, then the first line of the standard input should contain a single integer - themaximal number of kids that can be invited to the party so that it is a success.

The second line of the standard output should contain the numbers of kids to be invited, separated by single spaces, inincreasing order. Should there be more correct answers your programme should write out any oneof them.

9 4
12
9 6
4 6
7 9
1 2
2 1
9 7
7 6
4 5
7 8
8 9
3 4
4 3
5
1 3 5 6 8