function isBalanced(s) {
    let stack = [];
    let matchingBrackets = {
        '(': ')',
        '{': '}',
        '[': ']'
    };
    
    for (let char of s) {
        if (matchingBrackets[char]) {
            stack.push(char);
        } else {
            let top = stack.pop();
            if (matchingBrackets[top] !== char) {
                return 'NO';
            }
        }
    }
    return stack.length === 0 ? 'YES' : 'NO';
}