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
import math
import bisect
import itertools
import random
import re

def main():
    n, m = map(int, input().split())
    A = []
    for i in range(n):
        A.append(input())
    ans = 0
    for i in range(n - 1):
        for j in range(m - 1):
            B = []
            B.append(A[i][j])
            B.append(A[i][j+1])
            B.append(A[i+1][j])
            B.append(A[i+1][j+1])
            if sorted(B) == sorted(list('face')):
                ans += 1
    print(ans)

if __name__ == "__main__":
    main()
