#include <bits/stdc++.h>
#define fore(i, a, b) for (signed i = (a), i##_last = (b); i < i##_last; ++i)
#define fort(i, a, b) for (signed i = (a), i##_last = (b); i <= i##_last; ++i)
#define ford(i, a, b) for (signed i = (a), i##_last = (b); i >= i##_last; --i)
#define fi first
#define se second
#define pb push_back
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using namespace std;
using ll = long long;
using ld = long double;
template<class A, class B> bool maxi(A &a, const B &b) {return (a < b) ? (a = b, true):false;};
template<class A, class B> bool mini(A &a, const B &b) {return (a > b) ? (a = b, true):false;};
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
const int maxN = 55, maxK = 10005, inf = 0x3f3f3f3f;
int n, l, r, k, a[maxN], dp[maxN][maxN][maxK];
int DP(int x, int y, int z) {
if (x == l)
return DP(r + 1, y, z);
if (y > r)
return 0;
if (dp[x][y][z] < 0) {
const int d = abs(x - y);
dp[x][y][z] = inf;
mini(dp[x][y][z], a[y] + DP(x, y + 1, z));
if (x <= n) {
mini(dp[x][y][z], DP(x + 1, y, z));
if (d <= z)
mini(dp[x][y][z], DP(x + 1, y + 1, z - d) + a[x]);
}
}
return dp[x][y][z];
}
void subtask3() {
memset(dp, -1, sizeof(dp));
cout << DP(1, l, k) << '\n';
}
void subtask4() {
cout << 0 << '\n';
}
void input() {
cin >> n >> l >> r >> k;
fort(i, 1, n)
cin >> a[i];
}
int main() {
#ifdef LOCAL
freopen("input.INP", "r", stdin);
#endif // LOCAL
cin.tie(0) -> sync_with_stdio(0);
cout.tie(0);
input();
if (n <= 50)
subtask3();
else
subtask4();
return 0;
}
