Valid Bracket Sequence Checker

This problem requires you to determine whether a given sequence of brackets is valid. A bracket sequence is considered valid if every opening bracket has a corresponding closing bracket and the pairs of brackets are properly nested.

Formally, for a string s consisting of characters from the set \(\{ '(', ')', '{', '}', '[', ']' \}\), the sequence is valid if it satisfies the following condition:

\[ \text{A sequence is valid} \iff \text{every opening bracket has a matching closing bracket and the order of the brackets is correct.} \]

For example, the sequences "(())" and "{[()()]}" are valid, while "([)]" and "((()" are not.

inputFormat

The input consists of a single line containing a string s which represents the sequence of brackets.

Input Format:

[s]

outputFormat

Output a single line containing YES if the bracket sequence is valid, and NO otherwise.

Output Format:

YES
or
NO

## sample

{[()()]}

YES