s = input()

#print(s)



## choose which to remove

rev = s[::-1]
prevChar = "nic"
findFlip = ""

leaveIndex = -1

minuses = 0
pluses = 0


for i, c in enumerate(rev):
    #print(i, c)
    if (prevChar == "nic"):
        prevChar = c
        continue
    if (prevChar == c):
        if c == "-":
            minuses += 1
        else:
            pluses += 1

        #print("plus one")
        prevChar = "nic"

    prevChar = c

print(min(pluses, minuses)+abs(pluses-minuses))

"""
findFlip = prevChar
leaveIndex = len(s) - leaveIndex
print(prevChar, findFlip, leaveIndex)
"""