class Result {
    
    private static final String B_ROUND  = "()";
    private static final String B_SQUARE = "[]";
    private static final String B_CURLY  = "{}";
    
    private static String getBracketType(Character bracketCh) {
        return getBracketType("" + bracketCh);
    }
    
    private static String getBracketType(String bracketStr) {
        switch(bracketStr) {
            case "(":
            case ")":
                return B_ROUND;
            case "[":
            case "]":
                return B_SQUARE;
            case "{":
            case "}":
                return B_CURLY;
            default:
                return "";
        }
    }
    
    private static Character getExpectedOpenBracketCh(String curBracketType) {
        switch (curBracketType) {
            case B_ROUND:
                return '(';
            case B_SQUARE:
                return '[';
            case B_CURLY:
                return '{';
            default:
                return 'd';
        }
    }
    
    /*
     * Complete the 'isBalanced' function below.
     *
     * The function is expected to return a STRING.
     * The function accepts STRING s as parameter.
     */

    public static String isBalanced(String s) {
        // Write your code here
        Stack<Character> bracketsStack = new Stack<>();

        System.err.println(""); System.err.println("");
        System.err.println("s=" + s);

        for (int sIdx = 0 ; sIdx < s.length() ; sIdx++) {

            Character sCh = s.charAt(sIdx);
            String curBracketType = getBracketType(sCh);
            
            // System.err.println("sIdx=" + sIdx + " | sCh=" + sCh + " | " +
            //                    "curBracketType=" + curBracketType);

            switch(sCh) {
                case '(':
                case '[':
                case '{':
                    bracketsStack.push(sCh);
                    break;

                case ')':
                case ']':
                case '}':
                
                    if (bracketsStack.isEmpty()) {
                        return "NO";
                    }

                    Character peekStackTopBracket =
                                  bracketsStack.peek();

                    Character expectedOpenBracket = 
                                  getExpectedOpenBracketCh(curBracketType);
                                  
                    // System.err.println("peekStackTopBracket=" + 
                    //                    peekStackTopBracket + " | " +
                    //                    "expectedOpenBracket=" + 
                    //                    expectedOpenBracket);

                    if (peekStackTopBracket != expectedOpenBracket) {
                        return "NO";
                    }

                    bracketsStack.pop();
                    break;
            }
        }
        
        if (!bracketsStack.isEmpty()) {
            return "NO";
        }

        return "YES";
    }

}