Why am I getting negative time in submission of MAXEP?

alt text

In the interactive problem ‘Max and Electrical Panel’ Dec18 contest

https://discuss.codechef.com/questions/141708/interactive-problems-and-the-way-to-deal-with-them/141760

Negative submission time usually implies that you are violating some constraints set by the problem. For example, in this problem, you might have exceeded the number of coins used.

//