#include <bits/stdc++.h>
#define N 2000001
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
const ll INF = 1e18, MOD = 998244353, MOD2 = 1e6 + 3;
ll s, e, h, n, a[N];
priority_queue<ll, vector<ll>> lwing;
priority_queue<ll, vector<ll>, greater<ll>> rwing;
ll solve (string testname) {
lwing.push (a[0]);
rwing.push (a[0]);
ll l = 0, r = 0;
ll ans = 0;
for (int i = 1; i < n; i++) {
l += h, r -= h;
ll ltop = lwing.top () - l;
ll rtop = rwing.top () - r;
if (a[i] < ltop) {
lwing.pop ();
lwing.push (a[i] + l), lwing.push (a[i] + l);
rwing.push (ltop + r);
ans += abs (a[i] - ltop);
} else if (rtop < a[i]) {
rwing.pop ();
rwing.push (a[i] + r), rwing.push (a[i] + r);
lwing.push (rtop + l);
ans += abs (a[i] - rtop);
} else {
lwing.push (a[i] + l);
rwing.push (a[i] + r);
}
}
return ans;
}
int main () {
/*cin >> s >> e >> h;
mt19937 rng;
n = 300;
while (s <= e) {
string testname = "test_" + to_string (s++);
ofstream fout (testname + ".in");
int lh = uniform_int_distribution<int>(h / 10, max ((int) 1e9, 10 * h))(rng);
fout << n << '\n' << << '\n';
for (int i = 0; i < n; i++) {
a[i] = uniform_int_distribution<int>(1, 1000000000)(rng);
fout << a[i] << ' ';
}
fout << endl;
fout.close ();
}*/
cin >> n >> h;
for (int i = 0; i < n; i++) {
cin >> a[i];
}
cout << solve ("");
}
