A coastal monitoring station strings a line of buoys along a shipping channel, each anchored to a fixed point on the seabed. Every buoy reports its current horizontal drift from its own anchor, measured in meters: a negative reading means the buoy has drifted toward shore, a positive reading means it has drifted toward open sea, and a reading near zero means the buoy is sitting almost exactly on its anchor.

Given the drift readings from every buoy on the line, find the single reading that is closest to zero. If two or more readings are tied for the smallest distance from zero, report the positive one, since a seaward drift is treated as the higher-priority alert for the harbor patrol.

Input format

Line 1: an integer n — the number of buoys. Line 2: n space-separated integers d1 d2 ... dn — the drift readings, in meters.

Output format

Print a single integer: the drift reading closest to zero, breaking ties in favor of the positive value.

Constraints

1 <= n <= 1000 -1000 <= di <= 1000, and di != 0 for every i

5
2 -1 1 -3 4

1

3
-5 -10 -3

-3