#include<iostream>

 #include<cstring>

 #include<cstdlib>

 #include<cmath>

 #include<algorithm>

 #include<cstdio>

 #include<queue>

 #define maxn 500055

 #define ll long long

 using namespace std;

 int sum[maxn*],ls[maxn*],rs[maxn*],rt[maxn],cnt;

 int n,K,L,R;

 int pre[maxn],h[maxn],num[maxn],size[maxn];

 struct data {

     int w,pos;

     bool operator <(const data tmp) const{return w<tmp.w;}

 };

 priority_queue<data> q;

 void insert(int &x,int p,int l,int r,int k) {

     x=++cnt;

     sum[x]=sum[p]+,ls[x]=ls[p],rs[x]=rs[p];

     if(l==r) {return;}

     int mid=l+r>>;

     if(k<=mid) insert(ls[x],ls[p],l,mid,k);

     else insert(rs[x],rs[p],mid+,r,k);

 }

 int find(int x,int p,int l,int r,int k) {

 //    cout<<l<<' '<<r<<' '<<sum[ls[p]]<<' '<<sum[ls[x]]<<endl;

     if(l==r) return l;

     int mid=l+r>>;

     if(sum[ls[p]]-sum[ls[x]]>=k) return find(ls[x],ls[p],l,mid,k);

     else return find(rs[x],rs[p],mid+,r,k-(sum[ls[p]]-sum[ls[x]]));

 }

 int main() {

     scanf("%d%d%d%d",&n,&K,&L,&R);

     h[n+]=;

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

         int tmp;scanf("%d",&tmp);

         pre[i]=pre[i-]+tmp;

         h[i]=pre[i];

     }

     sort(h+,h+n+);

     int nn=;

     for(int i=;i<=n+;i++) if(h[i]!=h[nn]) h[++nn]=h[i];

     int hh=lower_bound(h+,h+nn+,)-h;

     insert(rt[],rt[],,n,hh);

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

         num[i]=lower_bound(h+,h+nn+,pre[i])-h;

         insert(rt[i+],rt[i],,n,num[i]);

     }

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

         if(i-L<) continue;

         int w=find(rt[max(i-R,)],rt[max(i-L+,)],,n,size[i]+);

         q.push((data){pre[i]-h[w],i});

     }

     ll ans=;

     for(int i=;i<=K;i++) {

         int w=q.top().w,pos=q.top().pos;

         ans+=(ll)w;

         size[pos]++;

         q.pop();

         int l=max(pos-R+,),r=pos-L+;

         if(size[pos]>=r-l+) continue;

         w=find(rt[l-],rt[r],,n,size[pos]+);

         w=pre[pos]-h[w];

         q.push((data){w,pos});

     }

     printf("%lld\n",ans);

 }