using System;

namespace BalancedBrackets
{
    class Program
    {
        static void Main(string[] args)
        {
            int signLeft = 0;
            int signRight = 0;
            int sign = 0;
            bool n = true;
            int lines = int.Parse(Console.ReadLine());
            for (int i = 0; i < lines; i++)
            {
                string symbols = Console.ReadLine();
                if (symbols == "(")
                {
                    signLeft += 1;
                }
                else if (symbols == ")")
                {
                    signRight += 1;
                }

                if (signLeft == 0 && signRight == 1)
                {
                    n = false;
                    sign = 1;
                }
                else if (signLeft == signRight && sign == 0)
                {
                    signLeft = 0;
                    signRight = 0;
                    n = true;
                }
                else
                {
                    n = false;
                }

            }

            if (n == true && sign == 0)
            {
                Console.WriteLine("BALANCED");
            }
            else
            {
                Console.WriteLine("UNBALANCED");
            }

        }
    }
}