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문제

You probably know about HTML, the mark up language used to create Web pages. HTML code contains a number of tags which are expected to follow certain rules.

In this problem we will be concerned with two of these rules:

  1. Every opening tag has to have a corresponding closing tag
  2. All tags must be properly nested.

Tags are marked by angled brackets which contain a keyword, such as <body> or <strong>. These are opening tags, the corresponding closing tags having / before the keyword, ie </body> and </strong>. It is possible for a tag to be both opening and closing, such as <br />, which complies with rule 1.

To be properly nested, if a tag is opened inside another tag, it must be closed before the other tag closes. For example

  • <body> <strong> </strong> </body> is properly nested
  • <body> <strong> </body> </strong> is not, and breaks rule 2.

If there are no tags present, the text complies with both rules.

Attributes may be present within an opening tag, such as

<a href="http://www.nzprogcontest.org.nz">This is a link</a>

The closing tag has only to match the keyword, not the attributes.

입력

Input will consist of a number of lines of HTML code, each line containing from 0 to 255 characters. The last line will contain a single # character – do not process this line. Within the text of each line will be zero or more tags. No angle bracket will be present unless it is part of a properly formed tag.

Determine whether or not the HTML meets the rules specified above.

출력

Output will consist of a single line for each line of input. The line will contain either the word legal, or the word illegal.

예제 입력

<body> <strong>Oops, this is</body> naughty </strong>
<body> <strong>Hello</strong> <br /> </body>
Just text, no tags.
<p> Oh dear, we are missing something.
<a href="http://www.nzprogcontest.org.nz">This is a link</a>
#

예제 출력

illegal
legal
legal
illegal
legal

힌트