#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define fi first
#define se second
#define debug(x) cout << #x << " => " << x << "\n";
const int mod = 1e9 + 7;
int n, k, l, p[10000005], idx;
int le, ri;
ll dp[10000005][2];
ll ans;
ll delivery(int N, int K, int L, int P[]) {
n = N, k = K, l = L;
for(int i = 0; i < n; i++) {
if(P[i]) p[++idx] = P[i];
}
n = idx;
if(n == 0) return 0;
le = 0, ri = 1;
for(; ri <= n; ri++) {
while(ri - le > k && le < ri)
le++;
assert(p[ri] >= 0 && p[ri] < l && p[le] >= 0 && p[le] < l);
dp[p[ri]][0] = dp[p[le]][0] + min(l, p[ri] * 2);
}
reverse(p + 1, p + n + 1);
le = 0, ri = 1;
for(; ri <= n; ri++) {
while(ri - le > k && le < ri)
le++;
assert(p[ri] >= 0 && p[ri] < l && p[le] >= 0 && p[le] < l);
dp[p[ri]][1] = dp[p[le]][1] + min(l, ((l - p[ri]) % l) * 2);
}
// ans = min(dp[p[1]][0], dp[p[n]][1]);
// for(int i = 2; i <= n; i++) {
// assert(p[i] >= 0 && p[i] < l && p[i - 1] >= 0 && p[i - 1] < l);
// ans = min(ans, dp[p[i]][0] + dp[p[i - 1]][1]);
// }
return ans;
}
