#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 105;
const int M = 10005;
const int inf = 1e9 + 7;
int dp[N+1][M+1][N+1];//0 indexli
void solve(){
int n,l,r,k;cin >> n >> l >> r >> k;
l--;r--;
int arr[n];
for(int i = 0;i<n;i++)cin >> arr[i];
for(int i = 0;i<=N;i++){
for(int j = 0;j<=M;j++){
for(int k = 0;k<=N;k++){
dp[i][j][k] = inf;
}
}
}
dp[0][k][0] = 0;
for(int i = 0;i<n;i++){
for(int j = 0;j<N;j++){
for(int k = 0;k<=(r-l+1);k++){
if(dp[i][j][k] == inf)continue;
//cout << i << " " << j << " " << k << " = " << dp[i][j][k] << " " << (j - abs((l + k) - i)) << endl;
//al
if((j - abs((l + k) - i)) >= 0){
dp[i+1][(j - abs((l + k) - i))][k+1] = min(dp[i+1][(j - abs((l + k) - i))][k+1] , dp[i][j][k] + arr[i]);
//cout << " -> " << i+1 << " " << (j - abs((l + k) - i)) << " " << k+1 << " = " << dp[i+1][(j - abs((l + k) - i))][k+1] << endl;
}
//alma
dp[i+1][j][k] = min(dp[i+1][j][k] , dp[i][j][k]);
}
}
}
int ans = inf;
//cout << "ENDED" << endl;
for(int i = 0;i<N;i++){
//cout << n << " " << i << " " << r-l+1 << " -> " << dp[n][i][r-l+1] << endl;
ans = min(ans , dp[n][i][r-l+1]);
}
cout << ans << endl;
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);
int testcase = 1;//cin >> testcase;
while(testcase--)solve();
}
