Python The function f3 gets a string as a parameter. it checks that all alpha letters that appear in s appear both as small letters and also as big (capital) letters. It returns True or False accordingly. If no alpha letters at all then True is returned. Examples: f3 ('abcde ABCDE123') ==True f3 ('abcde ABCD123') ==False f3 ('abcdABCDE123') ==False def f3 (string): sl=set (string) s2=set ('abcdefghijklmnopqrstuvwxyz') s3=set ('ABCDEFGHIJKLMNOPQRSTUVWXYZ') return Complete the missing code. Requirements : Without recursion. Use sl, s2 and s3. Write your code in the designated place ONLY