s = eval(input())

print(("yes" if len(s)==len(list(set(s))) else "no"))
s = eval(input())

print(("yes" if len(s)==len(set(s)) else "no"))
s = eval(input())
print(("yes" if len(s) == len(list(set(s))) else "no"))

s = eval(input())
print(("yes" if len(s) == len(set(s)) else "no"))

-print(("yes" if len(s) == len(list(set(s))) else "no")) +print(("yes" if len(s) == len(set(s)) else "no"))