import java.io.*;

public class S5
{
    static int answer = 0;
    public static void main (String[] args) throws IOException
    {
	BufferedReader input = new BufferedReader (new FileReader ("DATA5.txt"));
	PrintWriter output = new PrintWriter (new FileWriter ("OUT5.txt"));
	for (int numRun = 1 ; numRun <= 5 ; numRun++)
	{
	    answer = 0;
	    int numWater = Integer.parseInt (input.readLine ());
	    int numCol = Integer.parseInt (input.readLine ());
	    int numRow = Integer.parseInt (input.readLine ());

	    String[] data = new String [numRow];
	    for (int i = 0 ; i < numRow ; i++)
	    {
		data [i] = input.readLine ();
	    }

	    char[] [] map = new char [numRow] [numCol];
	    for (int i = 0 ; i < data.length ; i++)
	    {
		for (int j = 0 ; j < data [i].length () ; j++)
		{
		    map [i] [j] = data [i].charAt (j);
		}
	    }

	    for (int i = 0 ; i < numWater ; i++)
	    {
		find (map, 0, 0);
	    }
	    input.readLine ();
	    output.println (answer);
	}
	output.close ();
    }


    static void find (char[] [] map, int x, int y)
    {
	/*map [x] [y] = '*';
	printOutArray (map);
	System.out.println ("X = " + x);
	System.out.println ("Y = " + y);
	System.out.println ();*/


	/*if (map [x] [y] == '#')
	    return;
	if (counter < steps [x] [y])
	    steps [x] [y] = counter;
	else
	    return;*/
	// printOutArray (steps);
	/*if (map [x] [y] == target)
	{
	    endX = x;
	    endY = y;
	}*/
	//   steps [x] [y] = counter;

	if (x < map.length - 1 && (map [x + 1] [y] != '#'))
	{
	    x = x + 1;
	    find (map, x, y);
	    return;
	}
	if (y < map [0].length - 1 && (map [x] [y + 1] != '#'))
	{
	    y = y + 1;
	    find (map, x, y);
	    return;
	}

	if (map [x] [y] == 'A')
	{
	    answer++;
	}
	map [x] [y] = '#';
    }


    static void printOutArray (char[] [] array)
    {
	for (int i = 0 ; i < array.length ; i++)
	{
	    for (int j = 0 ; j < array [i].length ; j++)
	    {
		System.out.print (array [i] [j]);
	    }
	    System.out.println ();
	}
    }
}