/* stack cell class */

class scell
{
    public final char symbol;
    public final int position;
    public final scell tail;
    public scell(char s, int p, scell t)
    { symbol=s; position=p; tail=t; }
} // scell

class sstack
{
    private scell tos = null; // top of stack

    public void push(char s, int p)
    {
	tos = new scell(s,p,tos);
    }

    // the following function tries to delete the top cell from the stack
    // it returns true if successful, and false if stack was null
    public boolean pop()
    {
	if (tos == null) return false;
	tos = tos.tail;
	return true;
    }

    // the following function returns the cell at the top of the stack
    public scell peek() { return tos; }

    public boolean isempty() { return tos==null; }
} // sstack


public class delimiters
{

    public static boolean leftd(char c)
    { return (c=='(' || c=='[' || c== '{'); }
      
    public static boolean rightd(char c)
    { return (c==')' || c==']' || c== '}'); }

    public static char leftcomp(char c)
    { switch (c)
	{ case ')' : return '(';
	  case ']' : return '[';
	  case '}' : return '{';
	  default : return c;
	}
    }

    public static void check(String s)
    {
	int i = 0;
	int n = s.length();
	char c;
	sstack stack = new sstack();
	boolean halt = false;
	while (i<n && !halt)
	    {
		c = s.charAt(i);
		if (leftd(c)) stack.push(c,i);
		else if (rightd(c))
		    {
			scell tos = stack.peek();
			if (tos == null)
			    {System.out.println("unmatched "+c+" at char "+i);
			     halt = true;
                            }
			else
			    {
				if (leftcomp(c)!=tos.symbol)
				    { System.out.println("mismatched "+tos.symbol+ " at char "+tos.position+" and "+c+" at char "+i); halt=true;; }
				else { stack.pop(); }
			    }
		    }
		i++;
	    } // while
	// at end of string, check if stack is empty
	if (!halt && !stack.isempty())
	    System.out.println("unmatched "+stack.peek().symbol+ " at "+stack.peek().position);
	else if (!halt) System.out.println("Everything is fine.");
    } // check

    public static void main(String[] args)
    {
	check(args[0]);
    }
}