#include <bits/stdc++.h>
using namespace std;
#if __has_include("all.hpp")
#include "all.hpp"
#else
#include <atcoder/all>
#endif
using namespace atcoder;

//遅延セグ木・区間更新・区間最大テンプレ

using S = long long;

using F = long long;

S op(S a, S b){ return max(a, b); }
//データとデータの演算
S e(){ return 0; }
//初期値(データ)
S mapping(F f, S x){ return f+x; }
//データと演算子の演算
F composition(F f, F g){ return f+g;} 
//演算子と演算子の演算
F id(){ return 0; }
//初期値(演算子)

int main(void){
    int n,b,c;
    cin>>n>>b>>c;
    c--;
    vector<long long>a(n);
    if(b==2)b=1;
    else b=0;
    for(int i=0;i<n;i++)cin>>a[i];
    vector<S> v(n+1, 0);
    lazy_segtree<S, op, e, F, mapping, composition, id> seg(v);
    for(int i=0;i<n;i++){
        seg.set(i+1,seg.prod(max(0,i-c),i+1-b));
        seg.apply(max(0,i-c),i+1,a[i]);
        //for(int j=0;j<=n;j++)cout<<seg.get(j)<<(j==n?"\n":" ");
    }
    cout<<seg.prod(max(0,n-c),n+1)<<endl;
    return 0;
}