CF1807A Plus or Minus

You are given three integers $ a $ , $ b $ , and $ c $ such that exactly one of these two equations is true: - $ a+b=c $ - $ a-b=c $ Output + if the first equation is true, and - otherwise.

N/A

N/A

In the first test case, $ 1+2=3 $ . In the second test case, $ 3-2=1 $ . In the third test case, $ 2-9=-7 $ . Note that $ c $ can be negative.