import sys for line in sys.stdin: open_symbol = '({[' close_symbol = ')}]' sequence_symbol=[] #state is tracker used to print answer once only state=0 for symbol in line: if symbol in open_symbol: sequence_symbol.append(symbol) elif symbol in close_symbol: if len(sequence_symbol) > 0: #get index of last element in sequence_symbol list #so that you can map with its opposite symbol index=open_symbol.index(sequence_symbol[len(sequence_symbol)-1]) #check closing symbol with last element of sequence_symbol if symbol == close_symbol[index]: sequence_symbol.pop() else: print('Unbalanced') state=1 break else: print('Unbalanced') state=1 break if len(sequence_symbol) is 0 and state is 0: print('Balanced') elif len(sequence_symbol) is not 0 and state is 0: print('Unbalanced')