Ok. Thanks for the comment.
Personally I don't like to nest commands inside commands. After some months, I'm sure I will forget the logic I have used :). Sometimes readability rewards you in a long term.

Your code will execute more linqs than mine :).

As you are using Linq, you can use it to output the number in a single line without needing to create lists, you can find out if the number you are looking for is odd or even (integers.Where(x => x % 2 == 0).Count() > 1 ? 1 : 0) so if this is 1 then we look for odd and 0 for even, we can then find where a variable fits the criteria integers.Where(z => (z % 2 == (*that code snippit before*))) and get the only value .First();, so now we have odd if the only number is odd and even if the only number is even.

Yours is way clearer though :P