sub order_line{  
    my @sorted_lines;
    foreach ( sort { _by_left( $a, $b ) } @lines ) { push @sorted_lines, $_ }
    print @sorted_lines;
}

sub _by_left {
    my ( $a, $b ) = @_;
    return lc( _on_left(  $a )) cmp lc( _on_left( $b )); 
    
}