import java.io.*;
import java.util.*;

public class Checker {
    public Stack stack;

    public Checker () {
	stack = new Stack ();
    }

    public boolean match (char opener, char closer) {
	switch (closer) {
	case '}':
	    return (opener == '{');
	case ')':
	    return (opener == '(');
	case ']':
	    return (opener == '[');
	default:
	    System.out.println ("Something insane has happened.");
	}
	return true;
    }    

  public void checkCloser (char closer) {
      if (stack.empty()) {
	  System.out.println ("Unbalanced");
	  System.exit (1);
	  return;
      }
      char opener = ((Character) stack.pop()).charValue();
      if (!match (opener, closer)) {
	  System.out.println ("Unbalanced");
	  System.exit (1);
      }
  }

  public void parseChar (char c) {
      switch (c) {
      case '{': case '(': case '[':
	  stack.push ((Object)(new Character (c)));
	  break;
      case '}': case ')': case ']':
	  checkCloser (c);
	  break;
      default:
      }
  }

    public void checkLine (String line) {
	for (int i = 0; i<line.length(); i++) {
	    parseChar (line.charAt(i));
	}
    }

    public void endOfInput () {
	if (stack.empty()) {
	    System.out.println ("All is well.");
	} else {
	    System.out.println ("Unbalanced.");
	}
    }

    public static void checkFile (String filename)
	throws FileNotFoundException, IOException {

	Checker checker = new Checker ();

	// open the file and create a BufferedReader for it
	BufferedReader in =
	    new BufferedReader (
	new FileReader (filename));
	String s;

	// use the BufferedReader to get lines from the file
	while (true) {
	    s = in.readLine();
	    if (s == null) break;
	    checker.checkLine (s);
	}
	checker.endOfInput ();
    }
}