balanced_brackets

lines = int(input())

opening_brckt = 0
closing_brckt = 0

for i in range(lines):
    symbol = input()
    if symbol == "(":
        opening_brckt += 1

    elif symbol == ")":
        closing_brckt += 1

    if opening_brckt - closing_brckt == 2:
        break

if opening_brckt == closing_brckt and opening_brckt != 0:
    print("BALANCED")
else:
    print("UNBALANCED")