PIET's CS department has been continuously organizing mock placement drives for students. If a student under-performs negative point is rewarded otherwise positive points is rewarded. The HOD wants to find consistency of a student. So, he wants to find out maximum consistent sum of a student score only if his/her overall rating is positive.
Help HOD in doing so.

Input

The first line contain number of drives N over which the analysis is to be done. The second line contains score of student in those N drives.

Output

Print a single integer i.e. the maximum consistent score of the student if it is positive otherwise output 0 (zero).

SAMPLE INPUT
8
-1 -4 4 -2 0 1 4 -5

SAMPLE OUTPUT
7

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