from collections import Counter

S = eval(input())

ctr = Counter(S)

m = ctr.most_common()[0][1]

print(('yes' if m==1 else 'no'))

S = eval(input())

print(('yes' if len(S) == len(set(S)) else 'no'))
from collections import Counter

S = eval(input())
ctr = Counter(S)
m = ctr.most_common()[0][1]
print(("yes" if m == 1 else "no"))

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

-from collections import Counter - -ctr = Counter(S) -m = ctr.most_common()[0][1] -print(("yes" if m == 1 else "no")) +print(("yes" if len(S) == len(set(S)) else "no"))