BalBrackets

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Pr6BalancedBrackets {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int lines = Integer.parseInt(reader.readLine());
        int count = 0;
        int flag1 = 0;
        int flag2 = 0;

        for (int i = 0; i < lines; i++) {
            String oneLine = reader.readLine();
            char symbol = oneLine.charAt(0);
            if (symbol == 40) {
                count++;
                flag1++;
                if (flag1 == 2) {
                    System.out.println("UNBALANCED");
                    return;
                }
                if (flag2 > 0) flag2--;
            } else if (symbol == 41) {
                flag2++;
                count++;
                if (flag2 == 2) {
                    System.out.println("UNBALANCED");
                    return;
                }
                if (flag1 > 0) flag1--;
            }
        }
        reader.close();
        if ((flag1 != flag2) && (count % 2 == 0)) {
            System.out.println("BALANCED");
        } else {
            System.out.println("UNBALANCED");
        }
    }
}