brackets

number_of_lines = int(input())
is_balanced = True
pattern = ''
for each_line in range(number_of_lines):
    command = input()
    if command == ')' and pattern == '':
        is_balanced = False
        break
    else:
        if command in '()':
            pattern += command
    if pattern == '()':
        is_balanced = True
        pattern = ''
    elif pattern == '((':
        is_balanced = False
        break

if is_balanced:
    print('BALANCED')
else:
    print('UNBALANCED')