HTML Tag Validator

You are given a string that contains HTML-like tags. The tags are in the format of <tag> for opening tags and </tag> for closing tags, where tag consists of alphanumeric characters. Your task is to determine if the tags are properly closed and nested.

The validation rules are:

• Every opening tag must have a corresponding closing tag.
• Tags must be closed in the correct order (i.e., last opened, first closed).
• Tag names are case-insensitive.

For example, the string <div><b>hello</b><i>world</i></div> is valid, while <div><b>hello</i></b></div> is not valid.

Mathematically, if we denote an opening tag by \( <tag> \) and closing tag by \( </tag> \), the string is valid if and only if the tags form a correct nested sequence.

inputFormat

The input consists of a single line string s which contains the HTML-like text.

Note: The input is provided via standard input (stdin).

outputFormat

Output True if the tags are valid and properly nested, otherwise output False.

Note: The output should be printed to standard output (stdout).

## sample

helloworld

True