HDU-1856-More is better



                                                 More is better

                                             Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 327680/102400 K (Java/Others)
                                             Total Submission(s): 22455    Accepted Submission(s): 8172

Problem Description

Mr Wang wants some boys to help him with a project. Because the project is rather complex,the more boys come, the better it will be. Of course there are certain requirements.

Mr Wang selected a room big enough to hold the boys. The boy 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 Wang's selection any two of them who are still in this room should be friends (direct or indirect), or there is only one boy left. Given all the direct friend-pairs, you should decide the best way.

 

Input

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)

 

Output

The output in one line contains exactly one integer equals to the maximum number of boys Mr Wang may keep.

 

Sample Input

41 23 45 61 641 23 45 67 8

 

Sample Output

42
题意：告诉你一堆人里面4种朋友关系，但若A认识B，B认识C，那么A也认识C，求一个朋友圈里面最多的朋友数量
题目链接：More is better
解题思路：
并查集的基本操作，但要将每个并查集优化，即每个点的父节点都指向根，这样保证一个树的高度就是他所含的朋友数，方便计算合并后的朋友数，此处值得思考的地方就是两个树的高度和就是合并后树的高度。
数据结构有时好依赖模板啊~
代码：