int main ()
{
    
    int m;
    int n;
    int i , j ,d;
    int count = 0;
    cin >> n;
    char a[n+2][n+2];
    char b[n+2][n+2];
    for ( i = 0; i <= n+1; i++ )
    {
        for ( j = 0; j <= n+1 ; j++ )
        {
            a[i][j] = '#';
            b[i][j] = '#';
        }
    }
    
    
    
    for ( i = 1; i <= n; i++ )
    {
        for ( j = 1; j <= n; j++ )
        {
            cin >> a[i][j];
            b[i][j] = a[i][j];
        }
    }
    
    cin >> m;
    
    for ( d = 1; d <= m; d++ )
    {
        if ( d % 2 == 1 )
        {
             for ( i = 1; i <= n; i++ )
             {
                 for ( j = 1; j <= n; j++ )
                 {
                     if ( a[i][j] == '@' )
                     {
                          b[i][j] = '@';
                          if ( b[i-1][j] != '#' )
                               b[i-1][j] = '@';
                          if ( b[i+1][j] != '#' )
                               b[i+1][j] = '@';
                          if ( b[i][j-1] != '#' )
                               b[i][j-1] = '@';
                          if ( b[i][j+1] != '#' )
                               b[i][j+1] = '@';
                     }
                 }
             }
        }
        if ( d % 2 == 0 )
        {
             for ( i = 1; i <= n; i++ )
             {
                 for ( j = 1; j <= n; j++ )
                 {
                     if ( b[i][j] == '@' )
                     {
                          a[i][j] = '@';
                          if ( a[i-1][j] != '#' )
                               a[i-1][j] = '@';
                          if ( a[i+1][j] != '#' )
                               a[i+1][j] = '@';
                          if ( a[i][j-1] != '#' )
                               a[i][j-1] = '@';
                          if ( a[i][j+1] != '#' )
                               a[i][j+1] = '@';
                     }
                 }
             }
        }
    }
    
    for ( i = 1; i <= n; i++ )
    {
        for ( j = 1; j <= n; j++ )
        {
            if ( m % 2 == 1 )
            {
                 if ( a[i][j] == '@' )
                      count++;
            }
            if ( m % 2 == 0 )
            {
                 if ( b[i][j] == '@' )
                      count++;
            }
        }
    }
    
    cout << count << endl;

    
}
    
    
