with open ('24_demo.txt') as f:
    s = f.readline()
s = s.replace('XYZXY', '33333').replace('XYZX', '2222').replace('XYZ', '111')
t = s.replace('X', ' ').replace('Y', ' ').replace('Z', ' ')
sp = t.split()
st = max(map(len, sp))
print(st)