A meteorology team releases a weather balloon fitted with an altimeter that logs the change in altitude between consecutive checkpoints during its ascent. The balloon launches from ground level, which is defined as altitude 0. At each checkpoint the altimeter records how much the altitude changed relative to the previous checkpoint (a positive value means it climbed, a negative value means it descended). Given this list of altitude changes, report the single highest altitude the balloon reaches at any checkpoint during the entire flight, counting the launch point itself as a checkpoint.

Input format

Line 1: an integer n — the number of recorded altitude changes. Line 2: n space-separated integers d_1 d_2 ... d_n — the altitude change recorded at each checkpoint (checkpoint i's altitude equals the launch altitude plus d_1 + d_2 + ... + d_i).

Output format

A single integer: the maximum altitude reached at any checkpoint from the launch (altitude 0) through the n-th checkpoint.

Constraints

• 1 <= n <= 100
• -100 <= d_i <= 100

5
3 -2 4 -1 2

6

7
-4 -3 -2 -1 4 3 2

0