26155

They always add up to an even number because if you add together the even numbers that are one less than each number you'll have an even number.Then if you add together the two that are left you get an even number.
If you do this with three odd numbers it would give you an odd number because you'll have three left to add together.
If you add up an even number of odd numbers you get an even number but if you have an odd number of odd numbers you get an odd number.