import sys sample = list(sys.stdin.readline().rstrip('\n')) count = 0 isOrdered = True while (isOrdered): max_seq = 0 seq = 1 last = sample[0] start = 0 end = -1 max_start, max_end = 0,-1 for i in range(1,len(sample)): if last != sample[i] and start: seq += 1 elif start: if seq % 2 == 0: end = i-1 if seq > max_seq: max_seq = seq max_start = start max_end = end else: end = i-2 if seq > max_seq: max_seq = seq-1 max_start = start max_end = end if last == sample[i]: start = i seq = 1 last = sample[i] if start: if seq % 2 == 0: end = i if seq > max_seq: max_seq = seq max_start = start max_end = end else: end = i-1 if seq > max_seq: max_seq = seq-1 max_start = start max_end = end rotated = sample[max_start:max_end+1] if rotated: sample = sample[0:max_start]+rotated[::-1]+sample[max_end+1:] count += 1 if max_seq == 0: isOrdered = False print(count)