Answer :

Tails
4 plus negative 3 is 1.

When adding negative numbers to positive ones, you should treat it as a normal subtraction, so 4-3.

4 + -3 = 1

The reason being is the three is negative and the four is positive.  So when you take a positive number and subtract it from a negative number - you get the difference of the two, the solution being one.

Feel free to see Leschell's example below in the comments. :)