Condensed HTML Tag Structure

You are tasked with checking the structure of HTML-like tags in a given string. Write a function that determines if all opening tags have a corresponding closing tag and that they are correctly nested. For simplicity, consider tags as strings formed by '<' and '>'. For example, '<div><span></span></div>' is valid, while '<div><span></div></span>' is not. Input The input consists of a single line containing the HTML-like tags string. Output Print 'VALID' if the structure is correct, otherwise print 'INVALID'. Example Input: <div><span></span></div> Output: VALID