>>> from dates import complete_year

>>> a = complete_year(57, 20)
>>> a
1957
>>> type(a)
<class 'int'>
>>> a = complete_year(16, 21)
>>> a
2016
>>> type(a)
<class 'int'>
>>> a = complete_year(66, 19)
>>> a
1866
>>> type(a)
<class 'int'>
>>> a = complete_year(86, 17)
>>> a
1686
>>> type(a)
<class 'int'>