#include<stdio.h>
#define INF -6e12
 
/*
C. George and Job
http://c...content-available-to-author-only...s.com/problemset/problem/467/C
*/
 
typedef long long int LL;
 
int n,m;
 
LL sum[5005];
LL arr[5005];
LL memo[5005][5005];
char calculated[5005][5005];
 
LL MAX(LL a,LL b)
{
	return a > b ? a : b;
}
 
LL dp(int index,int k)
{
	// Meaning that we have crossed the array boundary but we still have some 
	// m sized ranges to consider.
	if(index > n-m && k > 0)
	return INF;
 
	// All the k ranges have been considered for the sum. No need to recurse further.
	if(k == 0)
	return 0;
 
	// If the result for this subproblem has already been calculated, then return the result
	if(calculated[index][k] == 1)
	return memo[index][k];
 
	LL ans1,ans2;
 
	// Do not consider the current range. Move on to the next one
	ans1=dp(index+1,k);
 
	// Consider the current range and recurse on the next non overlapping range.
	ans2=dp(index+m,k-1) + sum[index];
 
	calculated[index][k]=1;
	memo[index][k]=MAX(ans1,ans2);
	return MAX(ans1,ans2);
}
 
int main()
{
	int i,k;
 
	scanf("%d%d%d",&n,&m,&k);
 
	for(i=0;i<n;i++)
	scanf("%ld",&arr[i]);
 
	for(i=0;i<m;i++)
	sum[0]+=arr[i];
 
	for(i=1;i<=(n-m);i++)
	{
		sum[i]=sum[i-1];
 
		sum[i]-= arr[i-1];
		sum[i]+= arr[m+i-1];
	}
 
	printf("%lld\n",dp(0,k));
 
	return 0;
}

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