import java.util.Deque;
import java.util.LinkedList;
import java.util.Map;
import java.util.Scanner;

class Solution {

    private static final Map<Character, Character> brackets = Map.of(
        ')', '(',
        '}', '{',
        ']', '['
    );
    
    private static boolean check(String input) {
        Deque<Character> stack = new LinkedList<>();

        for (char c : input.toCharArray()) {
            if (brackets.containsKey(c)) {
                if (stack.isEmpty()) return false;

                if (brackets.get(c) != stack.removeLast()) return false;

                continue;
            }

            stack.add(c);
        }

        return stack.isEmpty();
    }

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

        while (sc.hasNext()) {
            boolean isBalanced = check(sc.next());

            System.out.println(isBalanced ? "true" : "false");
        }

        sc.close();
    }
}