#include <bits/stdc++.h>
#define int long long
using namespace std;
int32_t main(){
int n, l, r, k;
cin>>n>>l>>r>>k;
l--,r--;
vector<int> arr(n);
for (int i = 0; i < n; ++i)
{
cin>>arr[i];
}
vector<vector<vector<int>>> dp(r-l+1,vector<vector<int>>(n-(r-l+1),vector<int>(k+1,-1)));
auto f = [&](int node, int node2, int kalan, auto f)->int{
if (node>=r-l+1) return 0ll;
if (node2>=n-(r-l+1)) return 0ll;
if (dp[node][node2][kalan]!=-1) return dp[node][node2][kalan];
dp[node][node2][kalan]=f(node,node2+1,kalan,f);
dp[node][node2][kalan]=max(dp[node][node2][kalan],f(node+1,node2,kalan,f));
int val = node2+1+node;
int pos = l-(node2+1);
if (node2>=l){
val=node2-l+1+(r-l-node);
pos=r+node2-l+1;
}
if (kalan>=val && arr[pos]<=arr[node+l]){
dp[node][node2][kalan]=max(dp[node][node2][kalan],f(node+1,node2+1,kalan-val,f)+arr[node+l]-arr[pos]);
}
return dp[node][node2][kalan];
};
int somma = 0;
for (int i = l; i <= r; i++){
somma+=arr[i];
}
int ans = f(0,0,k,f);
cout<<somma-ans<<endl;
}
