Problem: The Balance of the World

The world should be finely balanced. Positive vs. negative, light vs. shadow, and left vs. right brackets. Your mission is to write a program that judges whether a string is balanced with respect to brackets so that we can observe the balance of the world.

A string that will be given to the program may have two kinds of brackets, round ("( )") and square ("[ ]"). A string is balanced if and only if the following conditions hold.

* For every left round bracket ("("), there is a corresponding right round bracket (")") in the following part of the string.
* For every left square bracket ("["), there is a corresponding right square bracket ("]") in the following part of the string.
* For every right bracket, there is a left bracket corresponding to it.
* Correspondences of brackets have to be one to one, that is, a single bracket never corresponds to two or more brackets.
* For every pair of corresponding left and right brackets, the substring between them is balanced.



Input

The input consists of one or more lines, each of which being a dataset. A dataset is a string that consists of English alphabets, space characters, and two kinds of brackets, round ("( )") and square ("[ ]"), terminated by a period. You can assume that every line has 100 characters or less. The line formed by a single period indicates the end of the input, which is not a dataset.

Output

For each dataset, output "yes" if the string is balanced, or "no" otherwise, in a line. There may not be any extra characters in the output.

Sample Input


So when I die (the [first] I will see in (heaven) is a score list).
[ first in ] ( first out ).
Half Moon tonight (At least it is better than no Moon at all].
A rope may form )( a trail in a maze.
Help( I[m being held prisoner in a fortune cookie factory)].
([ (([( [ ] ) ( ) (( ))] )) ]).
.
.


Output for the Sample Input


yes
yes
no
no
no
yes
yes






Example

Input




Output

Solution (in JAVA):

Solution:
import java.util.*;

public class Main{
	void yes(){
		System.out.println("yes");
	}

	void no(){
		System.out.println("no");
	}

	public void run(){
		Scanner scan = new Scanner(System.in);
		while(true){
			String s = scan.nextLine();
			if(s.equals(".")) break;
			Deque<Integer> stack = new ArrayDeque<Integer>();
			String[] sArray = new String[s.length()];
			for (int i = 0; i < s.length(); i++) {
    			// ??????????????????????´???????
    			sArray[i] = String.valueOf(s.charAt(i));
			}
			/*
			for (int i = 0; i < sArray.length; i++) {
    			// "sArray"???1??????????????¨???
    			System.out.println("strArray???????´???????" + i + "?????????" + sArray[i]);
			}
			*/
			//System.out.println("0");
			for (int i=0;i<sArray.length;i++) {
    			if(sArray[i].equals("(")) stack.push(1);
    			if(sArray[i].equals("[")) stack.push(2);
    			//System.out.print("0");
    			if(sArray[i].equals(")")) {
    				Integer a = stack.poll();
    				if(a == null || a == 2) {
    					no();
    					break;
    				}
    			}
    			if(sArray[i].equals("]")){
    				Integer a = stack.poll();
    				if(a == null || a == 1){
						no();
    					break;
    				}
    			}
    			if(sArray[i].equals(".")){
    				if(stack.size() == 0) yes();
    				else no();
    			}
			}
        }
	}

    public static void main(String[] args){
                Main  app = new Main();
		app.run();
    }
}