#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <ll, ll>
#define pb push_back
#define ff first
#define ss second
const int N = 1e7+5;
ll dp[N];
ll F(ll x, int t, ll L){
ll cur = (t ? (L-x)*2 : x*2);
return min(L, cur);
}
ll delivery(int n, int K, int L, int p[]){
dp[0] = min(F(p[0], 1, L), F(p[0], 0, L));
int pos = 0;
set<pii> s;
s.insert({F(p[0], 1, L), 0});
for (int i = 1; i < n; i++){
if (i-K < 0) dp[i] = min(F(p[0], 1, L), F(p[i], 0, L));
else dp[i] = dp[i-K]+min(F(p[i-K+1], 1, L), F(p[i], 0, L));
dp[i] = min(dp[i], dp[i-1]+F(p[i], 1, L));
while(s.size() and (*s.begin()).ss < i-K+1) s.erase(s.begin());
if (s.size()) dp[i] = min(dp[i], (*s.begin()).ff);
s.insert({dp[i-1]+F(p[i], 1, L), i});
}
return dp[n-1];
}
// int main ()
// {
// ios::sync_with_stdio(false);
// cin.tie(0);
// int n, k, l;
// cin >> n >> k >> l;
// int p[n];
// for (int i = 0; i < n; i++) cin >> p[i];
// cout << delivery(n, k, l, p);
// }
