• [B] Honeycomb

  • 时间限制: 1000 ms　内存限制: 65535 K
  • 问题描述
  • Miku is separated with her friends,so she should go to search for them.But she should pass a big diamond honeycomb.She can only go down and get into adjacent room.As shown in graph.For example,if the edge length of diamond honeycomb is 4,the number of rooms is 1,2,3,4,3,2,1 from top to bottom.She should get into the bottom room to get out.
  • 输入
  • Input until EOF.
    Tnput a positive integer N(1<N<=30) means the edge length of diamond honeycomb.
  • 输出
  • You should calculate the number of different routes she can get out.
  • 样例输入
  • 3
4
  • 样例输出
  • 6
20
  • 提示
  • 无
  • 来源
  • hungar
  • 操作

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