sub _on_left {
    my ( $s ) = @_;
    my @words = split( /\s+/);
    my $word_level=3;
    return  $words[ scalar( @words ) - $word_level ];
}

##</code><code>##

sub _on_left {
    my ( $s ) = @_;
    my @words = split ' ', $s;
    my $word_level = 3;
    return  $words[ $word_level - 1 ];
}

##</code><code>##

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 )); 
    
}

##</code><code>##

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

##</code><code>##

sub order_line{  
    my @sorted_lines = sort _by_left @lines;
    print @sorted_lines;
}

sub _by_left {
    return lc( _on_left(  $a )) cmp lc( _on_left( $b )); 
    
}