#ifndef LOCAL
#include <bits/stdc++.h>
#endif
using namespace std;
#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
#pragma GCC target("avx2")
#define int int64_t
const int inf=1e18;
#ifdef LOCAL
#include "algo/debug.h"
#else
template <typename... Args>
void dummy(Args&&... args){}
#define ps dummy
#endif
#define f first
#define s second
template<class T> using V = vector<T>;
using vi = V<int>;
using vb = V<bool>;
using vs = V<string>;
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define len(x) (int)((x).size())
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define ai2 array<int,2>
#define ai3 array<int,3>
#define ai4 array<int,4>
#define ai5 array<int,5>
template<class T> int lwb(const V<T>& a, const T& b) { return lb(all(a),b)-begin(a); }
template<class T> int upb(const V<T>& a, const T& b) { return ub(all(a),b)-begin(a); }
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a=b, true : false; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a=b, true : false; }
#define pct __builtin_popcountll
#define ctz __builtin_ctzll
#define clz __builtin_clzll
constexpr int p2(int x) { return (int)1 << x; }
constexpr int bits(int x) { return x == 0 ? 0 : 63-clz(x); } // floor(log2(x))
template<class T>void UNIQUE(V<T>& v) { sort(all(v)); v.erase(unique(all(v)),end(v)); }
template<class T,class U>void erase(T& t, const U& u) { auto it = t.find(u); assert(it != end(t)); t.erase(it); }
template<class F> struct y_combinator_result {
F f;
template<class T> explicit y_combinator_result(T &&f): f(std::forward<T>(f)) {}
template<class ...Args> decltype(auto) operator()(Args &&...args) { return f(std::ref(*this), std::forward<Args>(args)...); }
};
template<class Fun> decltype(auto) yy(Fun &&fun) { return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun)); }
template<class T>
struct Venice {
int shift = 0;
multiset<T> s;
void ins(int x) {
x -= shift;
s.ins(x);
}
void erase(int x) {
x -= shift;
::erase(s, x);
}
T get_min() {
return *begin(s) + shift;
}
T get_max() {
return *rbegin(s) + shift;
}
};
void solve() {
int n, h; cin >> n >> h;
vi a(n);
for (int& i : a) cin >> i;
int b = 0;
Venice<int> L, R;
L.ins(a[0]); R.ins(a[0]);
for (int i = 1; i < n; i++) {
L.shift -= h;
R.shift += h;
int l = L.get_max(), r = R.get_min();
if (a[i] > r) {
b += a[i] - r;
L.ins(r);
R.erase(r);
R.ins(a[i]);
} else if (a[i] < l) {
b += l - a[i];
R.ins(l);
L.erase(l);
L.ins(a[i]);
} else {
L.ins(a[i]);
R.ins(a[i]);
}
}
cout << b << '\n';
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
solve();
return 0;
}
