Problem A: 校园科技节分组争霸赛

Problem A: 校园科技节分组争霸赛

[Creator : ]
Time Limit : 1.000 sec  Memory Limit : 128 MB

Solved: 18Submit: 41Statistics

Description

Input

Output

Sample Input Copy 

5
0 -1 -2 3 -4

Sample Output Copy 

24
Submit