[Usaco2007 China]Treasure 财富

时间限制:5s      空间限制:64MB

题目描述

 


输入格式

    1行输入N,之后N行每行输入一对整数,描述一条道路.


输出格式

 输出宝藏的埋藏方式种数.


样例输入

4
1 2
2 3
3 1
1 4

INPUT DETAILS:

Here is a drawing of the roads and the intersections.

                   4---1---2
                        \ /
                         3


样例输出

3

OUTPUT DETAILS:

The treasure can be buried at any intersection. However, burying it at
intersections 2 and 3 yields maps that are identical to each other. So the
total number of distinct treasure maps is 3.


提示

没有写明提示


题目来源

Gold