#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define fi first
#define se second
#define all(v) v.begin(),v.end()
#define allarr(a) a , a + n
#define ll long long
#define ull unsigned long long
#define pb push_back
#define fastio ios_base::sync_with_stdio(false) ; cin.tie(NULL); cout.tie(NULL)
typedef pair<int, int> pi;
typedef pair<ll,ll> pll;
typedef pair<int,pi> trp ;
typedef vector<pi> vpi;
typedef vector<pll> vpll ;
// int ab (int x ) { return (x>0?x:-x);
ll delivery(int N , int K , int L,int positions[]){
ll l = L, cur = 0 ,s=0, k = K ;
for(int i = 0 ; i< N ; i++ ){
s += min(abs(1LL*positions[i]-cur),l-abs(1LL*positions[i]-cur));
// cout << s << endl;
cur = positions[i] ;
k--;
if( k == 0 ){
s += min(cur,l-cur);
k = K ;
cur = 0 ;
}
}
if( k )s += min(cur,l-cur);
return s;
}
// int main(){
// int p[]={1,2,5};
// cout << delivery(3,2,8,p);
// }
