//********************************
//*????????? **
//*????? 1300012839 **
//*???2013.11.2**
//********************************
int main()
{
	int i,j,n,m,k,count = 0;
	char a[102][102][102];
	cin >> n;
	for(k=1;k<=101;k++)
		{
			for(i=0;i<=101;i++)
		  {
			for(j=0;j<=101;j++)
			a[k][i][j]='.';
	       }
	    }
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=n;j++)
		cin >> a[1][i][j];
	}
	cin >> m;
	for(k=1;k<m;k++)
		{
			for(i=1;i<=n;i++)
	          {
		       for(j=1;j<=n;j++)
		          {
			         if(a[k][i][j]=='.')
						 {
							 if((a[k][i-1][j]=='@')||(a[k][i+1][j]=='@')||(a[k][i][j+1]=='@')||(a[k][i][j-1]=='@'))
								 a[k+1][i][j]='@';
					      }
					 if(a[k][i][j]=='@')a[k+1][i][j]='@';
					 if(a[k][i][j]=='#')a[k+1][i][j]='#';
			      }
			   }
	    }
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=n;j++)
			if(a[m][i][j]=='@')count = count +1;
	}
	cout << count << endl;
	return 0;
}
