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.
#!/usr/bin/python3.5
n,m=[int(x) for x in input().split()]
if n<2 or m<2:
    print(0)
    quit()
c=0
mas=[]
for i in range(n):
    mas.append(input())
f=set('face')
for i in range(n-1):
    for j in range(m-1):
        k=set()
        k.add(mas[i][j])
        k.add(mas[i+1][j])
        k.add(mas[i][j+1])
        k.add(mas[i+1][j+1])
        if len(k&f)==4:
            c+=1
print(c)
    