CF467C.George and Job

The 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 $p_{1},p_{2},...,p_{n}$ . You are to choose $k$ pairs of integers:

$[l_{1},r_{1}],[l_{2},r_{2}],...,[l_{k},r_{k}] (1<=l_{1}<=r_{1}<l_{2}<=r_{2}<...<l_{k}<=r_{k}<=n; r_{i}-l_{i}+1=m),$ in such a way that the value of sum is maximal possible. Help George to cope with the task.

The first line contains three integers $n$ , $m$ and $k$ $(1<=(m×k)<=n<=5000)$ . The second line contains $n$ integers $p_{1},p_{2},...,p_{n}$ $(0<=p_{i}<=10^{9})$ .

Print an integer in a single line — the maximum possible value of sum.