#include <bits/stdc++.h>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
//#define int long long
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;
int32_t main() {
int n, l, r, K;
cin >> n >> l >> r >> K;
vector<int> v(n+1);
for(int i=1; i<=n; i++) cin >> v[i];
ll sum = 0;
for(int i=l; i<=r; i++) sum += v[i];
if(r == n) {
ll dp[l][n+1][K+1];
memset(dp, 0, sizeof(dp));
for(int i=1; i<l; i++) {
for(int j=l; j<=r; j++) {
for(int k=0; k<=K; k++) {
dp[i][j][k] = min(dp[i][j][k], dp[i-1][j][k]);
dp[i][j][k] = min(dp[i][j][k], dp[i][j-1][k]);
if(j - i <= k) dp[i][j][k] = min(dp[i][j][k], dp[i-1][j-1][k-j+i] + v[i] - v[j]);
}
}
}
cout << sum + dp[l-1][n][K] << '\n';
return 0;
}
return 0;
}
