#include <iostream>
#include <cstring>
#include <cmath>
using namespace std;
int f[105][10005], n, L, R, K, a[105];
int main() {
    cin >> n >> L >> R >> K;

    for (int i = 1; i <= n; i++)
        cin >> a[i];

    memset(f, 0x3f, sizeof(f));
    f[0][0] = 0;

    for (int i = 1; i <= n; i++) {
        for (int j = R - L; j >= 0; j--) {
            int v = abs(L + j - i);

            for (int k = 0; k <= K - v; k++) {
                f[j + 1][k + v] = min(f[j + 1][k + v], f[j][k] + a[i]);
            }
        }
    }

    int ans = 1 << 30;

    for (int i = 0; i <= K; i++) {
        ans = min(ans, f[R - L + 1][i]);
    }

    cout << ans << '\n';
    return 0;
}