A9927 | Face Detection

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.

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.

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