jaccard

import re

s1 = input()
s2 = input()
s1 = s1.lower()
s2 = s2.lower()
s1 = re.sub("[\s+,.?]", "", s1)
s2 = re.sub("[\s+,.?]", "", s2)
list1 = list(s1)
list2 = list(s2)
# print(list1)
# print(list2)
set1 = set(list1)
set2 = set(list2)
af1 = list(set1.intersection(set2))
af2 = list(set1.union(set2))
print("{:.2f}".format(len(af1) / len(af2)))