24 отрезок в котором не больше 3х C

s = open().readline()
l = 0
r = 0
answ = 1
c = 0
if s[0] == 'C':
    c = 1
while r != len(s) - 1:
    while r + 1 < len(s) and c + (s[r + 1] == 'C') <= 3:
        r += 1
        if s[r + 1] == 'C':
            c += 1
    answ = max(answ, r - l + 1)
    while s[l] != 'C':
        l += 1
    l += 1
    c -= 1
print(answ)