[Usaco2007 China]Treasure 财富

内存限制：64 MiB 时间限制：5 Sec

提交提交记录讨论

第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.