#include<iostream>
#include<queue>
using namespace std;
#define N 25
struct point{
  int x;
  int y;
};
queue<point> q;
char a[N][N];//存地图
bool v[N][N];
int dx[4]={0,1,0,-1};
int dy[4]={1,0,-1,0};
int w,h,cnt;
point start;
int main()
{
 
  //w列 h行 格子为h*w规格棋盘
  cin>>w>>h;
  for(int i=0;i<h;i++)
     for(int j=0;j<w;j++){
      cin>>a[i][j];
      if(a[i][j]=='@'){
          start.x=i;
          start.y=j;
      }
     }
  q.push(start);
  v[start.x][start.y]=true;
  while(!q.empty()){
    point header=q.front();
    for(int i=0;i<4;i++){
      point temper=header; 
      temper.x+=dx[i];
      temper.y+=dy[i];
      if(a[temper.x][temper.y]=='.'&&!v[temper.x][temper.y])q.push(temper);
      v[temper.x][temper.y]=true;
    }	
    q.pop();
    cnt++;
  }
cout<<cnt<<endl;
  return 0;
}