原题链接
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<iostream>
using namespace std;
const int maxn=25;
char mapp[maxn][maxn];
int vis[maxn][maxn];
int a,b;
int n,m;
int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};
int cnt;
void dfs(int x,int y){
vis[x][y]=1;
cnt++;
for(int i=0;i<4;i++){
int tx=x+dx[i];
int ty=y+dy[i];
if(tx<1||tx>n||ty<1||ty>m) continue;
if(mapp[tx][ty]=='#') continue;
if(vis[tx][ty]) continue;
dfs(tx,ty);
}
return ;
}
int main(){
while(cin>>m>>n&&m||n){
cnt=0;
memset(vis,0,sizeof(vis));
memset(mapp,0,sizeof(mapp));
for(int i=1;i<=n;i++)
for(int j=1;j<=m;j++){
cin>>mapp[i][j];
if(mapp[i][j]=='@') {
a=i;
b=j;
}
}
dfs(a,b);
cout<<cnt<<endl;
}
return 0;
}
