def CheckAnswer(pairs, gluingSequence):
    if not gluingSequence:
        return False
    def Glue(pairIndex):
        return ''.join(pairs[i][pairIndex] for i in gluingSequence)
    return Glue(0) == Glue(1)

def FindGluingSequence(pairs):
    # FIXME This should actually return something.
    return None

if __name__ == '__main__':
    pairs = [
        ('ab', 'a'),
        ('bbaaba', 'a'),
        ('b', 'bbbb'),
        ('bb', 'ab'),
    ]
    print CheckAnswer(pairs, [0, 2, 1, 3, 3, 2])
    print CheckAnswer(pairs, [2, 1, 3, 3, 2, 0])