s = open("") #твой текстовый файл
f = s.readline()
k = 0
kmax = 0
for i in range (0,len(f)-1):
if ((f[i]=='X') and (k % 3==0)) or ((f[i]=='Y') and (k % 3==1)) or ((f[i]=='Z') and (k % 3==2)):
k+=1
else:
kmax = max(k,kmax)
k = 0
kmax = max(k,kmax)
print(kmax)
