Mr Chen wants some students to help him with a project. Because the project is rather complex, the more students come, the better it will be. Of course there are certain requirements.
Mr Chen selected a room big enough to hold the students. The student who are not been chosen has to leave the room immediately.There are 10000000 boys in the room numbered from 1 to 10000000 at the very beginning. After Mr Chen's selection any two of them who are still in this room should be friends (direct or indirect), or there is only one student left. Given all the direct friend-pairs, you should decide the best way.
The first line of the input contains an integer n (0 ≤ n ≤ 100,000) - the number of direct friend-pairs. The following n lines each contains a pair of numbers A and B separated by a single space that suggests A and B are direct friends. (A ≠ B, 1 ≤ A, B ≤ 10000000)