2904: George and Job
[Creator : ]
Description
time limit per test
1 secondmemory limit per test
256 megabytesinput
standard inputoutput
standard outputThe new ITone 6 has been released recently and George got really keen to buy it. Unfortunately, he didn't have enough money, so George was going to work as a programmer. Now he faced the following problem at the work.
Given a sequence of n integers p1,p2,...,pn. You are to choose k pairs of integers:
in such a way that the value of sum 
is maximal possible. Help George to cope with the task.
Input
The first line contains three integers n, m and k (1≤(m×k)≤n≤5000). The second line contains n integers p1,p2,...,pn (0≤pi≤109).
Output
Print an integer in a single line − the maximum possible value of sum.
Examples
Input
5 2 1
1 2 3 4 5
Output
9
Input
7 1 3
2 10 7 18 5 33 0
Output
61