> 2 of the 3 possible sums would lead to an even sum (odd+odd=even, even+even=even, odd+even=odd) I think the conclusion is wrong, there are 4 cases: odd+odd=

> 2 of the 3 possible sums would lead to an even sum (odd+odd=even, even+even=even, odd+even=odd) I think the conclusion is wrong, there are 4 cases: odd+odd=even, even+even=even, odd+even=odd, even+odd=odd