# import re
#
# with open('24_7.txt', 'r') as file:
#     data = file.readline()
#
# data = re.sub('CD', '--', data)
#
# not_CD = r'(-?[^-]*)'
#
# CD_and_any = r'(?:--[^-]*){160}-?'
# la_CD_group = rf'(?=({CD_and_any}))'
#
# pattern = rf'{not_CD}{la_CD_group}'
#
# matches = re.findall(pattern, data)
#
# res = max([len(match[0] + match[1])
#            for match in matches])
# print(res)

f = open('24_7.txt').readline()
f = f.replace('CD', 'C D').split()
m = 0
for i in range(len(f)-161):
    a=''.join(f[i:i+161])
    m = max(m, len(a))
print(m)