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

def solve():
    n, m = map(int, input().split())
    tab = [list(input()) for x in range(n)]
    need = set(['f', 'a', 'c', 'e'])
    res = 0
    for row in range(n - 1):
        for col in range(m - 1):
            s = set()
            for r in range(row, row + 2):
                for c in range(col, col + 2):
                    s.add(tab[r][c])
            if need.issubset(s):
                res+=1
    return res

def run():
    if sys.hexversion == 50594544 : sys.stdin = open("test.txt")
    print(solve())

run()