#include<iostream>
#include<cstdio>
using namespace std;
int n,s,t;
long long a[100010],sum[100010],q[100010],ans;
int main()
{
    freopen("ggame.in","r",stdin);
    freopen("ggame.out","w",stdout);
    scanf("%d%d%d",&n,&s,&t);
    for(int i=1;i<=n;i++)
    {
        scanf("%lld",&a[i]);
        sum[i]=sum[i-1]+a[i];
    }
    int l=1,r=0;
    for(int i=s;i<=n;i++)
    {
        while(l<=r&&sum[q[l]]>=sum[i-s]) r--;
        r++;
        q[r]=i-s;
        while(q[l]<(i-t)) l++;
        ans=max(ans,sum[i]-sum[q[l]]);   
    }
    printf("%lld",ans);
    return 0;
}