A. Face Detectiontime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputThe 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.InputThe 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.OutputIn the single line print the number of faces on the image.ExamplesInput4 4xxxxxfaxxcexxxxxOutput1Input4 2xxcfaexxOutput1Input2 3faccefOutput2Input1 4faceOutput0NoteIn the first sample the image contains a single face, located in a square with the upper left corner at the second line and the second column:   In the second sample the image also contains exactly one face, its upper left corner is at the second row and the first column.In the third sample two faces are shown:   In the fourth sample the image has no faces on it.
Input4 4xxxxxfaxxcexxxxx
Output1
['implementation', 'strings', '*900']