//Written by: Jethro_
//----------------------
#include <bits/stdc++.h>
using namespace std;
int n, l, r, k;
void solve() {
cin >> n >> l >> r >> k;
vector<int> a(n + 1);
for (int i = 1; i <= n; ++i) {
cin >> a[i];
}
int m = (r - l + 1);
vector<vector<vector<int>>> dp(n + 1, vector<vector<int>>(m + 1, vector<int>(k + 1, 1e9)));
int res = 1e9;
for (int i = 0; i <= n; ++i) {
for (int j = 0; j <= k; ++j) {
dp[i][0][j] = 0;
}
}
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
for (int p = 0; p <= k; ++p) {
dp[i][j][p] = dp[i - 1][j][p];
if (p - abs(i - (l + j - 1)) >= 0) {
dp[i][j][p] = min({dp[i][j][p], dp[i - 1][j - 1][p - abs(i - (l + j - 1))] + a[i]});
}
if (j == m) res = min(res, dp[i][m][p]);
}
}
}
cout << res;
}
int main() {
cin.tie(NULL);
ios_base::sync_with_stdio(false);
solve();
}
//dp[i][j][k] = max(dp[i - 1][j][k], dp[i][j - 1][k], dp[i - 1][j - 1][k + abs(j - i)] - a[i] + a[j]);
