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.
import sys

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

img = []

for _ in range(m):
    img.append(list(input()))

count = 0

if m < 2 or n < 2:
    print(0)
    sys.exit(0)

for i in range(m - 1):
    for j in range(n - 1):
        f = [img[i][j], img[i+1][j], img[i][j+1], img[i+1][j+1]]
        if 'f' in f and 'a' in f and 'c' in f and 'e' in f:
            count += 1

print(count)
