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.
def main():
    [n_rows, n_cols] = [int(_) for _ in input().split()]
    rows = [input() for _ in range(n_rows)]
    face_count = 0

    for i in range(n_rows - 1):
        for j in range(n_cols - 1):
            chars = [rows[i][j], rows[i][j + 1], rows[i + 1][j], rows[i + 1][j + 1]]
            chars.sort()

            if ''.join(chars) == 'acef':
                face_count += 1

    print(face_count)


if __name__ == '__main__':
    main()
