/*//////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
//BOCA Online Contest Administrator
//    Copyright (C) 2003-2012 by BOCA Development Team (bocasystem@gmail.com)
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//    You should have received a copy of the GNU General Public License
//    along with this program.  If not, see <http://www.gnu.org/licenses/>.
////////////////////////////////////////////////////////////////////////////////
// Last modified 05/aug/2012 by cassio@ime.usp.br
/*hex1 e hex2 sao strings hexa
 *devolve a soma das duas
 */
var hexchr="0123456789abcdef";
function bighexsoma (hex1, hex2){ 
	if (hex1.length > hex2.length) {
		a = hex2;
		hex2 = hex1;
		hex1 = a;
	}
	while (hex1.length < hex2.length)
		hex1 = '0' + hex1;

	sobra = 0;
	resultado = "";
	for(x = hex1.length-1; x>=0; x--) {
		if (hex1.charAt(x) > '9') op1 = hex1.charCodeAt(x)-hexchr.charCodeAt(10)+10; 
		else			  op1 = hex1.charCodeAt(x)-hexchr.charCodeAt(0);
		if (hex2.charAt(x) > '9') op2 = hex2.charCodeAt(x)-hexchr.charCodeAt(10)+10; 
		else			  op2 = hex2.charCodeAt(x)-hexchr.charCodeAt(0);

		r = op1 + op2 + sobra;
		if (r > 15) {
			r -= 16;
			sobra = 1;
		} else sobra = 0;

		resultado = hexchr.charAt(r) + resultado;
	} 
	if (sobra == 1) 
		resultado = "1" + resultado;
	return resultado;
}
/*
 *hex1 e hex2 sao strings hexa
 *devolve a string que representa hex2 - hex1 
 */
function bighexsub (hex1, hex2) { 
	if (hex1.length == hex2.length) {
		i=0;
		while (hex1.charAt(i) == hex2.charAt(i) && i<hex1.length) i++;

		if (i>=hex1.length) return 0;
		if (hex1.charAt(i) > hex2.charAt(i)) {
			sinal="";
			a = hex2;
			hex2 = hex1;
			hex1 = a;
		} else sinal = "-";
	}
	else {
		if (hex1.length < hex2.length) sinal="-";
		else {
			sinal="";
			a = hex2;
			hex2 = hex1;
			hex1 = a;
		}
		while (hex1.length < hex2.length)
			hex1 = "0" + hex1;
	}

	sobra = 0;
	resultado = "";
	for(x=hex1.length-1; x>=0; x--) { 
		if (hex1.charAt(x) > '9') op1 = hex1.charCodeAt(x)-hexchr.charCodeAt(10)+10; 
		else			  op1 = hex1.charCodeAt(x)-hexchr.charCodeAt(0);
		if (hex2.charAt(x) > '9') op2 = hex2.charCodeAt(x)-hexchr.charCodeAt(10)+10; 
		else			  op2 = hex2.charCodeAt(x)-hexchr.charCodeAt(0);

		r = op2 - op1 - sobra;
		if (r < 0) {
			r += 16;
			sobra = 1;
		} else sobra = 0;

		resultado = hexchr.charAt(r) + resultado;
	} 
	return sinal + resultado;
}