#include "bits/stdc++.h"
#define int long long
#define all(v) v.begin() , v.end()
#define sz(a) (int)a.size()
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
struct Node{
Node* lc;
Node* rc;
int pri,sub,val,lazy;
Node(int x){
lc = rc = NULL;
sub = 1;
lazy = 0;
val = x;
pri = rng();
}
};
inline int get_sub(Node *rt){
if(!rt) return 0;
return rt -> sub;
}
inline void recalc(Node* rt){
if(!rt) return;
int u = rt -> lazy;
rt -> lazy = 0;
rt -> val += u;
if(rt -> lc) rt -> lc -> lazy += u;
if(rt -> rc) rt -> rc -> lazy += u;
rt -> sub = 1 + get_sub(rt -> lc) + get_sub(rt -> rc);
}
Node* merge(Node* a,Node* b){
recalc(a), recalc(b);
if(!a || !b) return (!a ? b : a);
if(a -> pri > b -> pri){
a -> rc = merge(a -> rc, b);
recalc(a);
return a;
}
else{
b -> lc = merge(a, b -> lc);
recalc(b);
return b;
}
}
array<Node*,2> split_by_size(Node* a,int k){
recalc(a);
if(!a) return {NULL, NULL};
if(!k) return {NULL, a};
if(get_sub(a -> lc) >= k){
auto X = split_by_size(a -> lc, k);
a -> lc = X[1];
recalc(a);
return {X[0], a};
}
else{
auto X = split_by_size(a -> rc, k - get_sub(a -> lc) - 1);
a -> rc = X[0];
recalc(a);
return {a, X[1]};
}
}
array<Node*,2> split_by_key(Node* a,int k){
recalc(a);
if(!a) return {NULL, NULL};
if(a -> val <= k){
auto X = split_by_key(a -> rc, k);
a -> rc = X[0];
recalc(a);
return {a, X[1]};
}
else{
auto X = split_by_key(a -> lc, k);
a -> lc = X[1];
recalc(a);
return {X[0], a};
}
}
int Max(Node* rt){
recalc(rt);
if(!rt) return 0;
if(rt -> rc) return Max(rt -> rc);
return rt -> val;
}
int Min(Node* rt){
recalc(rt);
if(!rt) return 0;
if(rt -> lc) return Min(rt -> lc);
return rt -> val;
}
Node* Insert(Node* rt, int val){
recalc(rt);
auto X = split_by_key(rt, val);
return merge(merge(X[0],new Node(val)),X[1]);
}
void _(){
int n, k;
cin >> n >> k;
int ans = 0;
Node* T = NULL;
for(int i=1;i<=n;i++){
int val; cin >> val;
if(i > 1){
auto X = split_by_size(T, i - 1);
int l = Max(X[0]), r = Min(X[1]);
if(val < l) ans += l - val;
else if(val > r) ans += val - r;
T = merge(X[0], X[1]);
}
T = Insert(T, val);
T = Insert(T, val);
auto X = split_by_size(T, i);
X[0] -> lazy -= k;
X[1] -> lazy += k;
T = merge(X[0], X[1]);
}
cout << ans << '\n';
}
int32_t main(){
cin.tie(0); ios::sync_with_stdio(0);
int tc=1;//cin >> tc;
while(tc--) _();
return 0;
}
