#include <boxes.h>
#include <bits/stdc++.h>
#define lli long long int
using namespace std;
const int MAX = 1e7;
lli l[MAX], r[MAX];
lli delivery(int n, int k, int MOD, int p[])
{
for(int i=0;i<n;i++) l[i] = (p[i]<<1) + (i-k>=0) ? l[i-k] : 0;
for(int i=n-1;i>=0;i--)
{
int rev = ( MOD-p[i] )%MOD;
r[i] = (rev<<1) + (i+k<=n-1) ? r[i+k] : 0;
}
lli ret = min( r[0] , l[n-1] );
for(int i=0;i<n-1;i++) ret = min( ret , l[i] + r[i+1] );
lli cyc = MOD<<1;
if(n == k) ret = min( ret , cyc );
else
{
ret = min(ret , r[k] + cyc );
ret = min(ret , l[n-k-1] + cyc );
}
for(int i=0;i+k+1<n;i++) ret = min( ret , l[i] + r[i+k+1] + cyc );
return ret;
}
