N24

with open('24.txt') as f:
    s = f.readline()
    bad = ['X', 'Y', 'Z']
    for k in bad:
        s.replace(k, '*')
    s.replace('**', '#')
    a = s.split('#')
    kmax = 1

    t = a[0]
    k = len(t) + 1
    if t[-1] == '*':
        k -= 1
    if s[0] == '#' and t[0] != '*':
        k += 1
    kmax = max(k, kmax)

    t = a[-1]
    k = len(t) + 1
    if t[0] == '*':
        k -= 1
    kmax = max(k, kmax)

    for t in a:
        k = len(t) + 2
        if t[0] == '*':
            k -= 1
        if t[-1] == '*':
            k -= 1
        kmax = max(k, kmax)
print(kmax)