24

with open('c8c8a1ca-a3d8-461f-b43b-3473a40a7d83.txt', 'r') as file:
    a = file.readline()

cur_dist = 1
max_dist = 1
a_counter = 0
last_pos = 0

i = 0
while i < len(a):
    if a[i] == 'A':
        a_counter += 1
    if a_counter == 0:
        cur_dist += 1
    elif a_counter == 1:
        cur_dist += 1
        last_pos += 1
    elif a_counter == 2:
        max_dist = max(max_dist, cur_dist)
        cur_dist = 1
        a_counter = 0
        i -= last_pos - 1
        last_pos = 0
    i += 1


print(max_dist)