using System;

class BalancedBrackets
{
    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());
        bool balanced = true;
        bool searchOpening = true;
        bool searchClosing = false;
        for (int i = 0; i < n; i++)
        {
            string line = Console.ReadLine();
            if (searchOpening)
            {
                if (line == "(")
                {
                    searchOpening = false;
                    searchClosing = true;
                }
                else if (line == ")")
                {
                    balanced = false;
                }
            }
            else if (searchClosing)
            {
                if (line == ")")
                {
                    searchOpening = true;
                    searchClosing = false;
                }
                else if (line == "(")
                {
                    balanced = false;
                }
            }
        }
        Console.WriteLine((balanced && searchOpening) ? "BALANCED" : "UNBALANCED");
    }
}