with open ('24_demo.txt') as f:
    s = f.readline()
s = s.replace('XYZXY', '3').replace('XYZX', '2').replace('XYZ', '1')
t = s.replace('X', ' ').replace('Y', ' ').replace('Z', ' ')
def F(x):
    if '3' in x[:-2:-1] or  '2'  in x[:-2:-1]:
        return ' '
    else:
        return x
sp = t.split()
si = iter(sp)
sz = tuple(map(F, si))
def G(y):
    return y.replace('2', '2222').replace('3', '33333').replace('1', '111')
se = tuple(map(G, sz))
st = max(map(len, se))
print(st)