There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can move only on black tiles.
Write a program to count the number of black tiles which he can reach by repeating the moves described above.
Input
The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.
There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.
'.' - a black tile
'#' - a red tile
'@' - a man on a black tile(appears exactly once in a data set)
The end of the input is indicated by a line consisting of two zeros.
Output
For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).
Sample Input
6 9 ....#. .....# ...... ...... ...... ...... ...... #@...# .#..#. 11 9 .#......... .#.#######. .#.#.....#. .#.#.###.#. .#.#..@#.#. .#.#####.#. .#.......#. .#########. ........... 11 6 ..#..#..#.. ..#..#..#.. ..#..#..### ..#..#..#@. ..#..#..#.. ..#..#..#.. 7 7 ..#.#.. ..#.#.. ###.### ...@... ###.### ..#.#.. ..#.#.. 0 0
Sample Output
45 59 6 13
#include <iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
const int maxn=21+10;
char mp[maxn][maxn];
int step[4][2]= {1,0,0,1,-1,0,0,-1};
int n,m;
int ans;
void dfs(int i,int j)
{
ans++;
mp[i][j]='#';
for(int k=0; k<4; k++)
{
int x=i+step[k][0];
int y=j+step[k][1];
if(x>=0&&x<n&&y>=0&&y<m&&mp[x][y]=='.')
dfs(x,y);
}
}
int main()
{
while(scanf("%d%d",&m,&n),n+m)
{
int x,y;
for(int i=0; i<n; i++)
for(int j=0; j<m; j++)
{
cin>>mp[i][j];
if(mp[i][j]=='@')
{
x=i;
y=j;
}
}
ans=0;
dfs(x,y);
cout<<ans<<endl;
}
return 0;
}