Zeina just opened a restaurant, sadly due to COVID she might not be able to always profit from it.

After using statistics, she predicts the outcome of each day for the first N days.

Can you help Zeina calculate how much money she needs to lend from Rimawi (as you know treasures are into sketchy business) to make sure she ends up with a positive amount of profit each day.

First line is $n$ -- which is the number of days Zeina used statistics where $1 \le n \le 10^5$.

Second line contains $n$ integers $a_1, a_2, ..., a_n$ ($-10^4 \le a_i \le 10^4$) where the $a_i$ represents the expected profit for the $i^{th}$ day.

An integer representing her starting amount.