The '+' operation between the 2 numbers here takes The number of loops in these numbers and adds them together.

So 7 + 5 = 0 as (7 => has 0 loops and so does 5)

6 + 8 = 3 as (6 => has 1 loop and 8 => has 2 loops)

In that sense

**4 + 5 = 1** is the answer.