CF549A.Face Detection

普及/提高-

通过率：0%

AC君温馨提醒

该题目为【codeforces】题库的题目，您提交的代码将被提交至codeforces进行远程评测，并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供，我们无法保证该服务的稳定性，若提交后无反应，请等待一段时间后再进行重试。

题目描述

The developers of Looksery have to write an efficient algorithm that detects faces on a picture. Unfortunately, they are currently busy preparing a contest for you, so you will have to do it for them.

In this problem an image is a rectangular table that consists of lowercase Latin letters. A face on the image is a $2×2$ square, such that from the four letters of this square you can make word "face".

You need to write a program that determines the number of faces on the image. The squares that correspond to the faces can overlap.

输入格式

The first line contains two space-separated integers, $n$ and $m$ ( $1<=n,m<=50$ ) — the height and the width of the image, respectively.

Next $n$ lines define the image. Each line contains $m$ lowercase Latin letters.

输出格式

In the single line print the number of faces on the image.

输入输出样例

输入#1
```
4 4
xxxx
xfax
xcex
xxxx
```
输出#1
```
1
```
输入#2
```
4 2
xx
cf
ae
xx
```
输出#2
```
1
```
输入#3
```
2 3
fac
cef
```
输出#3
```
2
```
输入#4
```
1 4
face
```
输出#4
```
0
```

说明/提示

In the first sample the image contains a single face, located in a square with the upper left corner at the second line and the second column:

In the second sample the image also contains exactly one face, its upper left corner is at the second row and the first column.

In the third sample two faces are shown:

In the fourth sample the image has no faces on it.

首页