Given 2 strings, `a` and `b`, return a string of the form short+long+short, with the shorter string on the outside
and the longer string on the inside. The strings will not be the same length, but they may be empty ( length `0` ).
For example:
```python
solution("1", "22") # returns "1221"
solution("22", "1") # returns "1221"
```
def solution(a, b):
    if len(a) > len(b):
        return "{0}{1}{0}".format(b,a)
    else:
        return "{0}{1}{0}".format(a,b)
        

def solution(a, b):
    if len(a) > len(b):
        return "{0}{1}{0}".format(b,a)
    else:
        return "{0}{1}{0}".format(a,b)
        
