s = input()
k = 0
kmax = 0
for i in range(len(s)):
    if ((k % 2 == 0) and (s[i] == 'C')) or ((k % 2 == 1) and (s[i] == 'A')):
        k += 1
        if kmax < k:
            kmax = k
    else:
        k = 0
print(kmax)