cur = 0
res = 0
i = 0
seq = 'XYZ'

for ch in input():
  if ch == seq[i]:
    cur = cur + 1
    i = (i + 1) % len(seq)
  else:
    res = max(res, cur)
    cur = +(ch == seq[0])
    i = cur

res = max(res, cur)

print(res)