305434: CF1031A. Golden Plate
Memory Limit:256 MB
Time Limit:1 S
Judge Style:Text Compare
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Description
Golden Plate
题意翻译
你有一个盘子,你想在上面加些镀金。板是一个长方形,我们把它分成W×H单元。应该有K个要被金属的格子,第一个应该沿着板的边缘,第二个远离边缘2格,第三个4格等。每个环都有一个1格的宽度。这些环的第I个应该包括所有在其中心面积为(W−4(I−1))×(H−4(I−1))矩形中心在边缘上的格子 输入 W,H,K 输出 被镀金的格子数(一定要有换行!!!)题目描述
You have a plate and you want to add some gilding to it. The plate is a rectangle that we split into $ w\times h $ cells. There should be $ k $ gilded rings, the first one should go along the edge of the plate, the second one — $ 2 $ cells away from the edge and so on. Each ring has a width of $ 1 $ cell. Formally, the $ i $ -th of these rings should consist of all bordering cells on the inner rectangle of size $ (w - 4(i - 1))\times(h - 4(i - 1)) $ . ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF1031A/347cd2ee781d01fc5a8212010a9a488ef250ad46.png)The picture corresponds to the third example.Your task is to compute the number of cells to be gilded.输入输出格式
输入格式
The only line contains three integers $ w $ , $ h $ and $ k $ ( $ 3 \le w, h \le 100 $ , $ 1 \le k \le \left\lfloor \frac{min(n, m) + 1}{4}\right\rfloor $ , where $ \lfloor x \rfloor $ denotes the number $ x $ rounded down) — the number of rows, columns and the number of rings, respectively.
输出格式
Print a single positive integer — the number of cells to be gilded.
输入输出样例
输入样例 #1
3 3 1
输出样例 #1
8
输入样例 #2
7 9 1
输出样例 #2
28
输入样例 #3
7 9 2
输出样例 #3
40