#include<bits/stdc++.h>
using namespace std;
int n,m,ans = 0;
char a[25][25];
void dfs(int x,int y){
    int f = 0;
    if(x<0 || x==n || y<0 || y==m || a[x][y] == '#') return;
    if(a[x][y] == 'X') f = 1;
    if(f == 0) ans++; a[x][y] = 'X';
    dfs(x+1,y);
    dfs(x-1,y);
    dfs(x,y+1);
    dfs(x,y-1);
}
int main(){
    cin >> n >> m;
    int x,y;
    for(int i = 0;i<n;i++){
        for(int j = 0;j<m;j++){
            cin >> a[i][j];
            if(a[i][j] == '@'){
                x = i,y = j;
            }
        }
    }
    dfs(x,y);
    cout << ans;
    return 0;
}