#include <bits/stdc++.h>
#define sz(c) int(c.size())
#define rep(i,a,b) for (int i=a; i<(b); ++i)
#define per(i,a,b) for (int i=(b)-1; i>=(a); --i)
#define fore(c,...) for (auto __VA_ARGS__:(c))
using namespace std;
using ll = long long;
template<class T> bool umin(T &x,T y) { if (x<y) return 0; x=y; return 1; }
template<class T> bool umax(T &x,T y) { if (x>y) return 0; x=y; return 1; }
int main() {
cin.tie(0);
ios_base::sync_with_stdio(0);
cout<<fixed<<setprecision(10);
int N,L,R,K;
cin>>N>>L>>R>>K;
L--,R--;
vector<int> A(N);
fore(A,&i) cin>>i;
vector<int> a,b;
rep(i,0,N) if (i>=L && i<=R) b.emplace_back(i); else a.emplace_back(i);
int na=sz(a),nb=sz(b);
vector<vector<int>> best(nb+1,vector<int>(K+1,(int)1e9));
best[0][0]=0;
rep(j,0,nb) umin(best[j+1][0],best[j][0]+A[b[j]]);
rep(i,0,na) {
auto next=best;
rep(j,0,nb) {
int d=abs(a[i]-b[j]);
rep(k,0,K+1) {
umin(next[j+1][k],next[j][k]+A[b[j]]);
if (k>=d) umin(next[j+1][k],best[j][k-d]+A[a[i]]);
}
}
best=next;
}
cout<<*min_element(best[nb].begin(),best[nb].end())<<'\n';
}
