CF177C2.Party

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

To celebrate the second ABBYY Cup tournament, the Smart Beaver decided to throw a party. The Beaver has a lot of acquaintances, some of them are friends with each other, and some of them dislike each other. To make party successful, the Smart Beaver wants to invite only those of his friends who are connected by friendship relations, and not to invite those who dislike each other. Both friendship and dislike are mutual feelings.

More formally, for each invited person the following conditions should be fulfilled:

  • all his friends should also be invited to the party;
  • the party shouldn't have any people he dislikes;
  • all people who are invited to the party should be connected with him by friendship either directly or through a chain of common friends of arbitrary length. We'll say that people a1a_{1} and apa_{p} are connected through a chain of common friends if there exists a sequence of people a2,a3,...,ap1a_{2},a_{3},...,a_{p-1} such that all pairs of people aia_{i} and ai+1a_{i+1} ( 1<=i<p1<=i<p ) are friends.

Help the Beaver find the maximum number of acquaintances he can invite.

输入格式

The first line of input contains an integer nn — the number of the Beaver's acquaintances.

The second line contains an integer kk — the number of pairs of friends. Next kk lines contain space-separated pairs of integers ui,viu_{i},v_{i} — indices of people who form the ii -th pair of friends.

The next line contains an integer mm — the number of pairs of people who dislike each other. Next mm lines describe pairs of people who dislike each other in the same format as the pairs of friends were described.

Each pair of people is mentioned in the input at most once . In particular, two persons cannot be friends and dislike each other at the same time.

The input limitations for getting 30 points are:

  • 2<=n<=142<=n<=14

The input limitations for getting 100 points are:

  • 2<=n<=20002<=n<=2000

输出格式

Output a single number — the maximum number of people that can be invited to the party. If a group of people that meets all the requirements is impossible to select, output 0.

输入输出样例

  • 输入#1

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

    输出#1

    3

说明/提示

Let's have a look at the example.

Two groups of people can be invited: 1,2,3{1,2,3} and 4,5{4,5} , thus the answer will be the size of the largest of these groups. Group 6,7,8,9{6,7,8,9} doesn't fit, since it includes people 77 and 99 who dislike each other. Group 1,2,3,4,5{1,2,3,4,5} also doesn't fit, because not all of its members are connected by a chain of common friends (for example, people 22 and 55 aren't connected).

首页