#!/usr/bin/perl -w
use strict;

my @last_open_tag;  # index is indent level
my @last_open_tag_line;  # index is indent level
my $line = 0;
while (defined($_=<STDIN>)) {
	my $tabs;
	s/^(\t+)//;
	$tabs = length($1);
	print ">$tabs<\n";
	if (m,^<([^/\s>]+),) {
		# open tag or <foo.../> (or comment, in fact)
		$last_open_tag[$tabs] = $1;
		$last_open_tag_line[$tabs] = $line;
	} elsif (m,^</([^/\s>]+),) {
		# close tag
		if ($last_open_tag[$tabs] ne $1) {
			print "<$last_open_tag[$tabs]> ... </$1> : lines $last_open_tag_line[$tabs] ... $line\n";
		} else {
#				print "<$last_open_tag[$tabs]> ... </$1> : lines $last_open_tag_line[$tabs] ... $line\n";
		}
	}
	++$line;
}