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.
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std ;
int f(char ch)
{
    if(ch=='f')return 1;
    else if(ch=='a')return 2;
    else if(ch=='c')return 3;
    else if(ch=='e')return 4;
    else return 500;
}
int main()
{
    int n,m,i,j,k=0;
    cin >> n >> m ;
    char ch[n][m];
    for(i=0;i<n;i++)
    {
        for(j=0;j<m;j++)
        {
            cin >> ch[i][j];
            if(i>0&&j>0)
            {
                if(f(ch[i][j])+f(ch[i-1][j])+f(ch[i][j-1])+f(ch[i-1][j-1])==10)
                    k++;
            }
        }
    }
    cout << k ;
    return 0;
}
