#include<bits/stdc++.h>

using namespace std;

const int maxn=;

int n,l,r,a[maxn];

int q[maxn],head=,tail=;

int f[maxn];

int main()

{

    scanf("%d%d%d",&n,&l,&r);

    for(int i=;i<=n;i++)scanf("%d",&a[i]);

    for(int i=l;i<=n;i++){

        while(head<=tail && q[head]+r<i)head++;

        while(head<=tail && f[q[tail]]<f[i-l])tail--;

        q[++tail]=i-l;//不能直接用i,不然記個p當做時間也行(一樣效果

        f[i]=f[q[head]]+a[i];

    }

    int ans=;

    for(int i=n+-r;i<=n;i++)ans=max(ans,f[i]);

    printf("%d",ans);

}