#include <iostream>
#include <cstring>
#include <string>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
using namespace std;
int st,ed,n,sum[500001],ans=-2147483647,l=1,r=0,q[500001],x;
int main()
{
	scanf("%d%d%d",&n,&st,&ed);
	for(int i=1;i<=n;i++)scanf("%d",&x),sum[i]=sum[i-1]+x;
	q[r]=0;
	for(int i=st;i<=n;i++)
	{
		while(r>=l&&i-q[l]>ed)l++;
		while(r>=l&&sum[q[r]]>=sum[i-st])r--;
		q[++r]=i-st;
		ans=max(ans,sum[i]-sum[q[l]]);
	}
	printf("%d",ans);
	return 0;
}