#include <bits/stdc++.h>
using namespace std;
#define int long long
const int inf = 1e17, mod = 998244353, N = 5e6+5;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define rnd(l, r) uniform_int_distribution<int>(l, r)(rng)
int bp (int a, int n, int md) {
int res = 1, p = a;
while(n > 0) {
if(n & 1) res = res * p % md;
p = p * p % md;
n >>= 1;
};
return res;
};
int gcd(int a, int b, int & x1, int & y1) {
if(b == 0) {
x1 = 1;
y1 = 0;
return a;
};
int x = 0, y = 0;
int g = gcd(b, a%b, y, x);
// b * y + a % b * x = g
// b * y + a * x - b * (a/b)*x = g
// a * x + b * (y - (a/b)*x) = g
x1 = x;
y1 = y - (a/b) * x;
return g;
};
void solve() {
int n, h;
cin >> n >> h;
vector<int> a(n);
for(int &i : a) cin >> i;
int ans = 0, vl = 0, vr = 0;
priority_queue<int> l;
priority_queue<int, vector<int>, greater<int>> r;
l.push(a[0]);
r.push(a[0]);
for(int i = 1; i < n; i ++ ) {
vl -= h;
vr += h;
if(l.top() + vl <= a[i] && a[i] <= r.top() + vr) {
l.push(a[i] - vl);
r.push(a[i] - vr);
continue;
};
if(a[i] < l.top() + vl) {
int ls = l.top();
l.pop();
ans += ls - (a[i] - vl);
l.push(a[i] - vl);
l.push(a[i] - vl);
r.push(ls + vl - vr);
continue;
};
if(a[i] > r.top() + vr) {
int ls = r.top();
r.pop();
ans += (a[i] - vr) - ls;
r.push(a[i] - vr);
r.push(a[i] - vr);
l.push(ls + vr - vl);
continue;
};
};
cout << ans << '\n';
};
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int tt = 1;
//cin >> tt;
while( tt -- ) {
solve();
};
};
