s=eval(input());print(('yneos'[len(s)!=len(set(s))::2]))
s=eval(input());print(('yneos'[len(s)>len(set(s))::2]))
s = eval(input())
print(("yneos"[len(s) != len(set(s)) :: 2]))

s = eval(input())
print(("yneos"[len(s) > len(set(s)) :: 2]))

-print(("yneos"[len(s) != len(set(s)) :: 2])) +print(("yneos"[len(s) > len(set(s)) :: 2]))