Write regular expressions that describes the following
language:
The language over {0,1} that contains all and only the strings
that are base-2 representations of odd positive integers. Do not
allow leading 0s. (If you are more comfortable writing bulky
regular expressions than you are working in base-2, you may write a
regular expression for strings that are base-10 representations of
odd integers without leading 0s, using alphabet
{0,1,2,3,4,5,6,7,8,9}.)