file = open('8.txt')
s = file.readline()
for i in range(1, len(s)):
    if s[i] in 'OA' and s[i-1] in 'ABCD':
        s = s.replace(s[i-1:1+1], '**')
for i in range(len(s)):
    if s[i] != '*':
        s = s.replace(s[i], ' ')
s = s.split()
print(len(max(s, key = len)))