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
char mp[22][22];
int d[4][2]={{0,-1},{0,1},{1,0},{-1,0}};
int n,m,sum;
void dfs(int x,int y){
int i,temp,xx,yy;
if(x<=0||x>n||y<=0||y>m)
return;
sum++;
mp[x][y]='#';
for(i=0;i<4;i++){
xx=x+d[i][0];
yy=y+d[i][1];
if(mp[xx][yy]=='.')
dfs(xx,yy);
}
}
int main(){
int i,j,si,sj;
char temp;
while(1){
scanf("%d%d",&m,&n);
if(n==0&&m==0)
break;
sum=0;
//scanf("%c",&temp);
for(i=1;i<=n;i++){
for(j=1;j<=m;j++){
scanf("%1s",&mp[i][j]);
if(mp[i][j]=='@'){
si=i;
sj=j;
}
}
// scanf("%c",&temp);
}
// for(i=1;i<=n;i++){
//for(j=1;j<=m;j++)
// printf("%c ",mp[i][j]);
// printf("\n");
// }
dfs(si,sj);
cout<<sum<<endl;
}
return 0;
}
