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.

最新款 ITone 6 近日发布，乔治对此极为热衷，迫切想要购买。但不幸的是，他手头资金不足，因此乔治决定去当一名程序员赚钱。现在他在工作中遇到了如下问题：

给定一个由 $n$ 个整数组成的序列 $p_1, p_2, ..., p_n$。你需要从中选出 $k$ 对整数：

$$[l_1, r_1], [l_2, r_2], ..., [l_k, r_k] \quad (1 ≤ l_1 ≤ r_1 < l_2 ≤ r_2 < ... < l_k ≤ r_k ≤ n; \; r_i - l_i + 1 = m),$$

使得和式 的值尽可能大。请帮助乔治解决这一任务。

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 ≤ 109).

第一行包含三个整数 $n$、$m$ 和 $k$（满足 $1 \leq (m \times k) \leq n \leq 5000$）。第二行包含 $n$ 个整数 $p_1,\ p_2,\ \dots,\ p_n$（满足 $0 \leq p_i \leq 10^9$）。

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

在一行中输出一个整数——和的最大可能值。