#include<bits/stdc++.h>
using namespace std;
const int N=100005;
int n,s,t,a[N],ans=-0x3f3f3f3f;
deque<int> q;
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++){
        int x;
        scanf("%d",&x); a[i]=a[i-1]+x;
    }
    for(int i = s;i<=n;i++)
    {
        while(!q.empty()&&a[q.back()]>=a[i-s]) q.pop_back();
        q.push_back(i-s);
        while(q.front()<i-t) q.pop_front();
        ans=max(ans,a[i]-a[q.front()]);
    }
    printf("%d\n",ans);
    return 0;
}