import java.util.Scanner;
import fi.uef.cs.tra.*;

class Brackets {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		System.out.print("Give a string : ");

		String s = sc.nextLine();

		System.out.println(s);
		System.out.println(checkBracketPairs(s));


	} // main() 

	public static boolean checkBracketPairs(String m) {

		LinkedStack<String> bracketStack = new LinkedStack<String>();

		for (int i = 0; i < m.length(); i++) {

			char c = m.charAt(i);

			switch (c) {

				case '(' : bracketStack.push(")"); break;
				case '[' : bracketStack.push("]"); break;
				case '{' : bracketStack.push("}"); break;

				case ')' :
				case ']' :
				case '}' :
						   if (bracketStack.isEmpty()) {
							   System.out.print(m.charAt(i));
							   System.out.println(" without opening first");
							   return false;
						   }
						   if (! m.substring(i, i+1).equals(bracketStack.peek())) {
							   System.out.print("Wrong:" + m.charAt(i));
							   System.out.print(", expected " +bracketStack.peek());
							   return false;
						   } else
							   bracketStack.pop();
			} // switch
		} //for 

		if (bracketStack.isEmpty())
			return true;

		while (! bracketStack.isEmpty()) {
			System.out.print(bracketStack.pop());
			System.out.println(" expected");
		}
		return false;

	} // checkBracketPairs()


} // class