#include <iostream>
#include <queue>
#include <fstream>
#include <iomanip>
#include <cmath>
#include <cassert>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>
#include <complex>
using u32 = unsigned;
using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using f64 = double;
using f80 = long double;
using namespace std;
using pt = complex<f80>;
#define ALL(x) begin(x), end(x)
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
#define N 200005
int n;
i64 s[N], m, c, h;
int main()
{
ShinLena;
cin >> n >> h;
priority_queue<i64> l;
priority_queue<i64, vector<i64>, greater<i64>> r;
i64 ll{}, lr{}, ymin{}, c{};
cin >> s[1];
l.push(s[1]);
r.push(s[1]);
ll += h;
lr += h;
ymin = s[1] + h;
for (int i = 2; i <= n; ++i)
{
cin >> s[i];
if (s[i] >= r.top() + lr)
{
int nl = r.top() + lr;
r.pop();
r.push(s[i] - lr);
r.push(s[i] - lr);
c += abs(s[i] - nl);
ymin = r.top() + lr;
l.push(nl + ll);
}
else if (s[i] >= l.top() - ll)
{
r.push(s[i] - lr);
l.push(s[i] + ll);
ymin = s[i];
}
else
{
int nr = l.top() - ll;
l.pop();
l.push(s[i] + ll);
l.push(s[i] + ll);
c += abs(nr - s[i]);
ymin = nr;
r.push(nr - lr);
}
ymin += h;
//cout << ymin << ' ' << c << endl;
ll += h;
lr += h;
}
cout << c;
return 0;
}
