#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using ld = long double;
#define rep(i, a, b) for (auto i = (a); i < (b); ++i)
#define per(i, a, b) for (auto i = (b); i-- > (a);)
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) static_cast<int>((x).size())
template <class T>
bool uin(T& a, const T& b) {
return a > b ? a = b, true : false;
}
template <class T>
bool uax(T& a, const T& b) {
return a < b ? a = b, true : false;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
ll h;
cin >> n >> h;
vector<int> a(n);
for (auto& x : a) cin >> x;
priority_queue<ll> L, R;
ll shift = 0;
auto push_L = [&](auto y) { L.push(y + shift); };
auto push_R = [&](auto y) { R.push(-(y - shift)); };
auto get_L = [&]() { return L.top() - shift; };
auto get_R = [&]() { return -R.top() + shift; };
ll val = 0;
push_L(a[0]);
push_R(a[0]);
rep(i, 1, n) {
const auto x = a[i];
shift += h;
const auto tl = get_L();
const auto tr = get_R();
if (x < tl) {
L.pop();
push_L(x);
push_L(x);
push_R(tl);
val += tl - x;
} else if (x > tr) {
R.pop();
push_R(x);
push_R(x);
push_L(tr);
val += x - tr;
} else {
push_L(x);
push_R(x);
}
}
cout << val << '\n';
}
