S = input()

nx = 0
ny = 0

memo = set()
memo.add((nx, ny))

da = [0, 1]
db = [0, -1]
dc = [1, 0]
for s in S:
    if s == "a":
        dx, dy = da
        if dx != 0:
            da[0] *= -1
        else:
            db, dc = dc, db
            da[0] *= -1
            da[1] *= -1
            db[0] *= -1
            db[1] *= -1
            dc[0] *= -1
            dc[1] *= -1
    elif s == "b":
        dx, dy = db
        if dx != 0:
            db[0] *= -1
        else:
            da, dc = dc, da
            da[0] *= -1
            da[1] *= -1
            db[0] *= -1
            db[1] *= -1
            dc[0] *= -1
            dc[1] *= -1
    else:
        dx, dy = dc
        if dx != 0:
            db[0] *= -1
        else:
            da, db = db, da
            da[0] *= -1
            da[1] *= -1
            db[0] *= -1
            db[1] *= -1
            dc[0] *= -1
            dc[1] *= -1
    nx += dx
    ny += dy
    memo.add((nx, ny))


print(len(memo))