#include<bits/stdc++.h>

 #define pa pair<int,int>

 #define CLR(a,x) memset(a,x,sizeof(a))

 using namespace std;

 typedef long long ll;

 const int maxn=5e5+,logn=,inf=5e5+;

 inline ll rd(){

     ll x=;char c=getchar();int neg=;

     while(c<''||c>''){if(c=='-') neg=-;c=getchar();}

     while(c>=''&&c<='') x=x*+c-'',c=getchar();

     return x*neg;

 }

 int N,K,L,R;

 int sum[maxn],tmp[maxn];

 int rot[maxn],pct,cnt[maxn*logn],ch[maxn*logn][];

 int tim[maxn],ori[maxn];

 priority_queue<pa > q;

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

     p=++pct;cnt[p]=cnt[pre]+;

     if(l<r){

         int m=l+r>>;

         if(x<=m) ch[p][]=ch[pre][],insert(ch[pre][],ch[p][],l,m,x);

         else ch[p][]=ch[pre][],insert(ch[pre][],ch[p][],m+,r,x);

     }

 }

 int query(int pre,int p,int l,int r,int k){

     if(k>cnt[p]-cnt[pre]) return -inf;

     if(l==r) return l;

     int w=cnt[ch[p][]]-cnt[ch[pre][]],m=l+r>>;

     if(k<=w) return query(ch[pre][],ch[p][],l,m,k);

     else return query(ch[pre][],ch[p][],m+,r,k-w);

 }

 int main(){

     //freopen("","r",stdin);

     int i,j,k;

     N=rd(),K=rd();L=rd(),R=rd();

     for(i=;i<=N+;i++) tmp[i]=sum[i]=sum[i-]+rd();

     sort(tmp+,tmp+N+);int mm=unique(tmp+,tmp+N+)-tmp-;

     for(i=;i<=N+;i++){

         int x=lower_bound(tmp+,tmp+mm+,sum[i])-tmp;

         ori[x]=sum[i];sum[i]=x;

         // printf("%d %d\n",ori[x],sum[i]);

     }

     for(i=;i<=N+;i++){

         insert(rot[i-],rot[i],,inf,sum[i]);

         // printf("%d\n",cnt[rot[i]]);

     }

     ll ans=;

     for(i=L+;i<=N+;i++){

         int x=query(rot[max(i-R-,)],rot[i-L],,inf,tim[i]=);

         q.push(make_pair(ori[sum[i]]-ori[x],i));

     }

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

         int p=q.top().second;ans+=q.top().first;

         // printf("%d %d\n",p,ans);

         q.pop();tim[p]++;

         int x=query(rot[max(p-R-,)],rot[p-L],,inf,tim[p]);

         if(x==-inf) continue;

         // printf("%d %d %d\n",p,tim[p],x);

         q.push(make_pair(ori[sum[p]]-ori[x],p));

     }

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

     return ;

 }