S = input()

s = set()
s.add((0,0))
x = 0
y = 0
flag = True
sita = 'a'
migi = 'b'
hidari = 'c'
for i in S:
    if i == sita:
        if flag:
            y -= 1
            flag = not flag
        else:
            y += 1
            flag = not flag
        s.add((x,y))
    elif i == migi:
        x += 1
        flag = not flag
        migi,hidari = hidari,migi
        s.add((x,y))
    else:
        x -= 1
        flag = not flag
        migi,hidari = hidari,migi
        s.add((x,y))
print(len(s))