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)
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<cstdio>
#include<cmath>
#include<string.h>
#include<queue>
using namespace std;
int N,M;
char map[21][21];
int vis[21][21];
int moveto[4][2]={0,1,1,0,0,-1,-1,0};
int ans=1;
struct node{
int x;
int y;
}Node;
void bfs(int x,int y)
{
Node.x=x;
Node.y=y;
queue<node>q;
q.push(Node);
vis[x][y]=1;
while(!q.empty())
{
node top=q.front();
q.pop();
for(int k=0;k<4;k++)
{
int newx=top.x+moveto[k][0];
int newy=top.y+moveto[k][1];
if(map[newx][newy]=='.'&&newx>=0&&newx<M&&newy>=0&&newy<N&&!vis[newx][newy])
{
Node.x=newx;
Node.y=newy;
q.push(Node);
vis[newx][newy]=1;
ans++;
}
}
}
}
int main(){
while(~scanf("%d %d",&N,&M)&&N&&M)
{
getchar();
ans=1;
memset(vis,0,sizeof(vis));
for(int i=0;i<M;i++)
{
scanf("%s",&map[i]);
}
for(int i=0;i<M;i++)
{
for(int j=0;j<N;j++)
{
if(map[i][j]=='@')
{
int startx=i;
int starty=j;
bfs(startx,starty);
}
}
}
printf("%d\n",ans);
}
}