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.
#! python

n, m = map(int, input().split())

counter = 0

img = [input() for _ in range(n)]

if n > 1 and m > 1:
    for y in range(n - 1):
        for x in range(m - 1):
            f = set(img[y][x:x+2] + img[y+1][x:x+2])

            if len(f) == 4 and 'x' not in f:
                counter += 1

print(counter)

