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, m = map(int, input().split())
    hi, res = [0], 0
    for _ in range(n):
        lo = [{'x': 0, 'f': 1, 'a': 2, 'c': 4, 'e': 8}[c] for c in input()]
        res += sum(f + a + c + e == 15 for f, a, c, e in zip(hi, hi[1:], lo, lo[1:]))
        hi = lo
    print(res)


if __name__ == "__main__":
    main()
