class Solution{

public static void main(String []argh)
{
    Scanner sc = new Scanner(System.in);

    while (sc.hasNext()) {
     String s = sc.nextLine();
     int n = s.length();
     int counter = 0;
     int counter1 = 0;
     if(s.startsWith("}") || s.startsWith("]") || s.startsWith(")")){
        System.out.println("false");
     }else if(s.endsWith("(") || s.endsWith("{") || s.endsWith("[")){
         System.out.println("false");
     }else {

        for (int i = 0; i < n; i++) {
            if (s.charAt(i) == '(' || s.charAt(i) == '[' || s.charAt(i) == '{') {
                counter++;
            }
            if (s.charAt(i) == ')' || s.charAt(i) == ']' || s.charAt(i) == '}') {
                counter1++;
            }
        }
        if (counter == counter1) {
          System.out.println("true");
        } else {
          System.out.println("false");
        }
    }
 }

} }