What Can Plus/Minus Get Us?

Logic Level 3

$\Large 1 \ \square \ 2 \ \square \ 3 \ \square \ 4 \ \square \ 5 \ \square \ 6 \ \square \ 7$

If we only used $\large \color{#3D99F6}{+}$ and $\large \color{#D61F06}{-}$ in place of the boxes above, how many distinct values can we obtain?