def shorter_reverse_longer(a,b):
    return a+b[::-1]+a if len(a) < len(b) else b+a[::-1]+b

'''
Given 2 strings, a and b, return a string of the form:
 shorter+reverse(longer)+shorter.

In other words, the shortest string has to be put as prefix
 and as suffix of the reverse of the longest.

Strings a and b may be empty, but not null (In C# strings may also be null.
 Treat them as if they are empty.).
If a and b have the same length treat a as the longer producing b+reverse(a)+b
'''
