stack = input().strip()

prev = 0
num_p = 0
num_m = 0
for c in stack:
    if c == '+' and prev == '+':
        num_p += 1
    if c == '-' and prev == '-':
        num_m += 1
    prev = c

if stack[0] == '+':
    num_p += 1
else:
    num_m += 1

print(min(num_m, num_p))