306325: CF1180A. Alex and a Rhombus
Memory Limit:256 MB
Time Limit:1 S
Judge Style:Text Compare
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Description
Alex and a Rhombus
题意翻译
给你一个整数$n$,你需要求出从$1\times 1$开始扩展$n-1$次的格子数量。 每一次扩展,所有与当前格子有边相邻的格子都会被扩展进答案里。比如$n\le 3$的情形如下面这张图: ![](https://cdn.luogu.org/upload/vjudge_pic/CF1180A/ccf29660dcd8bd16597fff06e6153caa2bd347a9.png)题目描述
While playing with geometric figures Alex has accidentally invented a concept of a $ n $ -th order rhombus in a cell grid. A $ 1 $ -st order rhombus is just a square $ 1 \times 1 $ (i.e just a cell). A $ n $ -th order rhombus for all $ n \geq 2 $ one obtains from a $ n-1 $ -th order rhombus adding all cells which have a common side with it to it (look at the picture to understand it better). ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF1180A/ccf29660dcd8bd16597fff06e6153caa2bd347a9.png)Alex asks you to compute the number of cells in a $ n $ -th order rhombus.输入输出格式
输入格式
The first and only input line contains integer $ n $ ( $ 1 \leq n \leq 100 $ ) — order of a rhombus whose numbers of cells should be computed.
输出格式
Print exactly one integer — the number of cells in a $ n $ -th order rhombus.
输入输出样例
输入样例 #1
1
输出样例 #1
1
输入样例 #2
2
输出样例 #2
5
输入样例 #3
3
输出样例 #3
13