import string
def only_hexadecimal_digit_letters(s):
for ch in s:
if ch not in string.hexdigits:
return False
return True
s = "0123456789ABCDEF"
if only_hexadecimal_digit_letters(s):
print ("yes");
else:
print ("no");
s = "abcdefABCDEF"
if only_hexadecimal_digit_letters(s):
print ("yes");
else:
print ("no");
s = "012abcABC"
if only_hexadecimal_digit_letters(s):
print ("yes");
else:
print ("no");
s = "012abcABCXYZ"
if only_hexadecimal_digit_letters(s):
print ("yes");
else:
print ("no");
'''
run:
yes
yes
yes
no
'''