import sys

sample = list(sys.stdin.readline().rstrip('\n'))

count = 0
plus = []
minus = []
started = False
i=0

last = None
for s in sample:
	if last == s and not started:
		i=2
		started = True
	elif last == s and started:
		i+=1
	elif started:
		if last == '+':
			plus.append(i)
		else:
			minus.append(i)
		started = False
		i = 0
	last = s
if started:
	if last == '+':
		plus.append(i)
	else:
		minus.append(i)
	started = False
	i = 0

sum_plus,sum_minus = 0,0

for x in plus:
	sum_plus += x-1

for x in minus:
	sum_minus += x-1

if sum_minus > sum_plus:
	print(sum_minus)
else:
	print(sum_plus)