#include <bits/stdc++.h>
using namespace std;
#define sp " "
#define endl "\n";
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 105
const int modulo = 1e9 + 7;
int arr[N], dp[N][N][10005];
int32_t main()
{
fastio();
int n, l, r, k;
cin>>n>>l>>r>>k;
for (int i = 1; i <= n; i++){
cin>>arr[i];
}
int ans = 0;
for (int i = l; i <= r; i++){
ans += arr[i];
}
for (int i = r; i >= l; i--){
for (int j = n; j >= 1; j--){
if (j >= l && j <= r) continue;
for (int m = 0; m <= k; m++){
int nxt = j + 1;
if (nxt == l) nxt = r + 1;
int t1 = dp[i][nxt][m];
int t2 = dp[i + 1][j][m];
int t3 = 0;
if (m >= abs(i - j)) t3 = arr[j] - arr[i] + dp[i + 1][nxt][m - abs(i - j)];
dp[i][j][m] = min(t3, min(t1, t2));
}
}
}
cout<<dp[l][1][k] + ans<<endl;
cerr << "time taken : " << (float)clock() / CLOCKS_PER_SEC << " seconds\n";
}
