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 itertools
import math
from collections import defaultdict

def input_ints():
    return list(map(int, input().split()))

def solve():
    n, m = input_ints()
    s = []
    for i in range(n):
        s.append(input())
    c = sorted(list('face'))
    ans = 0
    for i, j in itertools.product(range(n-1), range(m-1)):
        x = [s[i][j], s[i+1][j], s[i][j+1], s[i+1][j+1]]
        if sorted(x) == c:
            ans += 1
    print(ans)


if __name__ == '__main__':
    solve()
