import java.util.Scanner;

public class BalancedBrackets {
   public static void main(String[] args) { main( new Scanner(System.in) ); }
   public static void main(String input) { main( new Scanner(input + "\nDONE") ); }
   
   public static void main(Scanner s) {
       while (!s.hasNext("DONE")) {
           System.out.println( removeAllBalanced(s.nextLine()).equals("") ? "YES" : "NO" );
           }
       }
    

   /* Read all balanced expressions (including those with no parens),
    * and return the remaining unbalanced remainder of the string.
    * remainder("[]{}") = ""   remainder("[a]b]c") = "]c"
    */
   static String removeAllBalanced( String s ) {
       if (s.equals("")) {
           return "";
           }
       else {
           if (contains(CLOSES,first(s))) {
               return s;
               }
           else if (contains(OPENS,first(s))) {
               String body = removeAllBalanced(rest(s));
               // body should start with the closing-bracket for first(s); if not s is unbalanced.
               return (body.equals("") || first(body) != mate(first(s))) ? s : removeAllBalanced(rest(body));
               }
           else { // s starts with a non-bracket; skip over it.
               return removeAllBalanced(rest(s));
               }          
           }
       }
  
       
    static final String OPENS  = "{[(<";   
    static final String CLOSES = "}])>";  // MUST be parallel to OPENS
    static boolean contains(String s, char c) { return s.contains(new Character(c).toString()); }
    static char mate( char opener ) { return CLOSES.charAt( OPENS.indexOf(opener) ); }
    static char first(String s) { return s.charAt(0); }
    static String rest(String s) { return s.substring(1); }

       
    }