#include <bits/stdc++.h>
#include "boxes.h"
using namespace std;
#define ll long long
#define endl "\n"
#define INF 1000000000
#define LINF 1000000000000000LL
#define pb push_back
#define all(x) x.begin(), x.end()
#define len(s) (int)s.size()
#define test_case { int t; cin>>t; while(t--)solve(); }
#define single_case solve();
#define line cerr<<"----------"<<endl;
#define ios { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cerr.tie(NULL); }
#define mod 1000000007LL
const int N = 1e7 + 5;
ll l[N], r[N];
ll delivery(int n, int k, int L, int p[])
{
for(int i = 0;i<n;i++)
{
if(i>=k)
{
l[i+1] = l[i-k+1] + 2*p[i];
}
else
{
l[i+1] = 2*p[i];
}
}
for(int i = n-1;i>=0;i--)
{
if(n-1-i>=k)
{
r[i] = r[i+k] + 2*(L-p[i]);
}
else
{
r[i] = 2*(L-p[i]);
}
}
ll ans = LINF;
for(int i = -1;i<n;i++)
{
ans = min(ans, l[i+1]+r[i+1]);
}
for(int i = 0;i<=n;i++)
{
if(i+k>n) break;
ans = min(ans, l[i]+L+r[i+k]);
}
return ans;
}
