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.Scanner;

public class Main {
  public static void main(String args[]) {
    Scanner sc = new Scanner(System.in);
    sc.useDelimiter("\\n");

    while(true) {
      String input = sc.next();
      if(input.equals(".")) {
        break;
      }

      char[] stack = new char[100];
      int position = 0;
      for(int i = 0; i < input.length(); i++) {
        char c = input.charAt(i);
        if(c == '(') {
          stack[position] = '(';
          position++;
        }
        if(c == '[') {
          stack[position] = '[';
          position++;
        }
        if(c == ')') {
          if(position > 0 && stack[position - 1] == '(') {
            position--;
          } else {
            position = -1;
            break;
          }
        }
        if(c == ']') {
          if(position > 0 && stack[position - 1] == '[') {
            position--;
          } else {
            position = -1;
            break;
          }
        }
      }

      if(position == 0) {
        System.out.println("yes");
      } else {
        System.out.println("no");
      }
    }
  }
}