HTML Tag Validator

You are given a string representing HTML content. Your task is to validate whether the HTML tags are correctly nested and closed. Tags are represented by '<tag>' for opening and '</tag>' for closing. Write a program that reads the HTML string and prints 'VALID' if the tags are correctly nested and 'INVALID' otherwise. Input format: - A single line containing the HTML string (e.g., '<div><span></span></div>'). Output format: - A single line containing either 'VALID' or 'INVALID'. Example: Input: <div><span></span></div> Output: VALID