Valid Parentheses Checker

Given a string consisting solely of the characters '(', ')', '{', '}', '[' and ']', determine whether the string forms a valid sequence of parentheses. A string is considered valid if every opening bracket has a corresponding closing bracket in the correct order.

Formally, the rules are:
1. Every opening bracket must be closed by the same type of bracket.
2. Opening brackets must be closed in the correct order.

Your task is to implement a program that reads a single string from standard input and prints "YES" if the string is valid, otherwise prints "NO".

inputFormat

The input consists of a single line containing a string S, which contains only the characters '(', ')', '{', '}', '[' and ']'. The string may be empty.

outputFormat

Output a single line: "YES" if the input string is a valid sequence of parentheses according to the rules, otherwise "NO".## sample

()

YES