s = input()
x = [(0, 0)]
a = (1, 0)
b = (0, 1)

def flip(c, a, b):
    if c == 'a':
        res_a = -a[0], -a[1]
        res_b = a[0] + b[0], a[1] + b[1]
    elif c == 'b':
        res_a = a[0] + b[0], a[1] + b[1]
        res_b = -b[0], -b[1]
    else:
        res_a = -b[0], -b[1]
        res_b = -a[0], -a[1]
    return res_a, res_b

for c in s:
    if c == 'a':
        newx = x[-1][0] + a[0], x[-1][1] + a[1]
    elif c == 'b':
        newx = x[-1][0] + b[0], x[-1][1] + b[1]
    else:
        newx = x[-1][0] - (a[0] + b[0]), x[-1][1] - (a[1] + b[1])
    a, b = flip(c, a, b)
    x.append(newx)

print(len(set(x)))