Answer in Python only please! Assume s is a string of lower case characters. write a program that pritns the longest substring of s in which the letters occur in alphabetical order. For example, if s = 'azcbobobegghakl', then your program should print Longest substring in alphabetical order is beggh in the case of ties, print the first substring. For example, if s = 'abcbcd', then your program should print Longest substring in alphabetical order is: abc