There is no least common enominator for this answer due to the fact that these numbers don't share a common factor (23 is odd number with only two factors: 1, 23; while 35 is odd number with 4 factors: 1, 5, 7, 35) other than 1.
*But if you do 1/1, it will be 1; so this won't work properly.
So the answer is 23/35.