Array.prototype.equal = function (a2) {
	if (!a2 || this.length != a2.length) return false;
	for (var i = 0, l = this.length; i < l; i ++) {
		if (this[i] != a2[i]) return false;
	}
	return true;
};

Array.prototype.sum = function () {
	for (var i = 0, l = this.length, s = 0; i < l; i ++) s += this[i];
	return s;
};

Array.prototype.toInt = function () {
	var a = [], i, l = this.length;
	for (i = 0; i < l; i ++) a.push(parseInt(this[i]));
	return a;
};