/*

     题意：选择k个m长的区间，使得总和最大

     01背包：dp[i][j] 表示在i的位置选或不选[i-m+1, i]这个区间，当它是第j个区间。

         01背包思想，状态转移方程：dp[i][j] = max (dp[i-1][j], dp[i-m][j-1] + sum[i] - sum[i-m]);

         在两个for循环，每一次dp[i][j]的值都要更新

 */

 #include <cstdio>

 #include <cstring>

 #include <algorithm>

 #include <cmath>

 using namespace std;

 typedef long long ll;

 const int MAXN = 5e3 + ;

 const int INF = 0x3f3f3f3f;

 ll a[MAXN];

 ll sum[MAXN];

 ll dp[MAXN][MAXN];

 int main(void)        //Codeforces Round #267 (Div. 2) C. George and Job

 {

     int n, m, k;

     while (scanf ("%d%d%d", &n, &m, &k) == )

     {

         memset (sum, , sizeof (sum));

         for (int i=; i<=n; ++i)    {scanf ("%I64d", &a[i]);    sum[i] = sum[i-] + a[i];}

         ll ans = ;

         for (int i=m; i<=n; ++i)

         {

             ll tmp = sum[i] - sum[i-m];

             for (int j=; j<=k; ++j)

             {

                 dp[i][j] = max (dp[i-][j], dp[i-m][j-] + tmp);

             }

             ans = max (ans, dp[i][k]);

         }

         printf ("%I64d\n", ans);

     }

     return ;

 }

 /*

 5 2 1

 1 2 3 4 5

 7 1 3

 2 10 7 18 5 33 0

 */