#include<bits/stdc++.h>

using namespace std;

#define ll long long

ll n, k, x;
vector<ll> v;


int main(){
  cin >> n >> k;
  for(int i = 0; i < n;i++){
    cin >> x;
    v.push_back(x);
  }
  sort(v.begin(), v.end());

  //ll prefix[n+5];
  //prefix[0] = 0;
  ll consta = v[0];
  for(ll i = 0; i < n;i++){
    v[i] -= consta;
    //cout << prefix[i] << " ";
  }
  //cout << endl;

  ll mn = 1000000000000000;
  ll sum = 0;
  //cout << sum << endl;
  for(ll i = 0; i < n;i++){
    //cout << v[i] << " " << i*k << endl;
    sum += abs(v[i] - i*k);
    //cout << sum << " i" << i << endl;
  }
  //cout << sum << endl;
  mn = min(mn, sum);
  for(ll i = 1; i < n;i++){
    sum += (i*abs((v[i] - v[i-1] - k)));
    sum -= abs(v[i] - v[i-1] - k);
    //cout << sum << " sum1" << endl;
    sum -= abs((v[i] - v[i-1] - k))*(n-i -1);
    //cout << sum << " sum2" << endl;
    mn = min(mn, sum);
  }

  cout << abs(mn) << endl;
}