$1 \ \square \ 2 \ \square \ 3 \ \square \ 4$ If we only used plus signs and minus signs in place of the boxes above, how many distinct values can we obtain?
\($1 \ \square \ 2 \ \square \ 3 \ \square \ 4$\)
+ + + = 10
+ + - = 2
+ - - = -4
- - - = -8
- + + = 6
- - + = 0
+ - + = 4
- + - = -2
