using System;

namespace balancedBrackets
{
    class Program
    {
        static void Main()
        {
            int num = int.Parse(Console.ReadLine());
            int opening = 0;
            int closing = 0;
            bool beenOpened = false;
            bool balanced = true;
            for (int i = 0; i < num; i++)
            {
                string input = Console.ReadLine();
                if (beenOpened && input == "(")
                {
                    Console.WriteLine("UNBALANCED");
                    balanced = false;
                    break;
                }
                else
                {
                    beenOpened = false;
                }
                if (input == "(")
                {
                    opening++;
                    beenOpened = true;
                }
                else if (input == ")")
                {
                    closing++;
                }
                if (input == "(" && i == num-1)
                {
                    Console.WriteLine("UNBALANCED");
                    balanced = false;
                    break;
                }

            }
            if (balanced)
            {
                if (opening == closing)
                {
                    Console.WriteLine("BALANCED");
                }
                else
                {
                    Console.WriteLine("UNBALANCED");
                }
            }
        }
    }
}