I am getting a WA in a single test case in Carol and Skulls. I think it is a tricky edge case but am not able to find the error.
Here, is the link to my solution.
Please help.
Thanks. 
your code fails here
1
1
-5
Expected output:-5
Your output:0
Answer should be -5 because in the question it is mentioned that you need to select atleast one element.
@hruday968 I’ve updated my code and the output to the given test case is -5 but still I get a WA. Here’s the link: https://www.codechef.com/viewsolution/14744946
@hruday968 I got an AC. It’s because I was turning in a negative modulo 1e9 + 7. I added 1e9+7 to the result and the moduloed it as the output. It was mentioned in the question, I somehow missed it. Anyways, thanks for your answer.