#include <functional>
#include <iostream>
#include <queue>
#include <vector>
int main() {
std::cin.tie(NULL)->sync_with_stdio(false);
int n;
long long h;
std::cin >> n >> h;
// dp[0][x]: y = |x - a[0]|
// dp[i+1][x] = min(dp[i][y], x - h <= y <= x + h) + |x - a[i+1]|
// inductively: dp[i] is a convex linear piecewise lines
// min x-h <= y <= x+h --> shift minimum range (xL, xR) -> (xL - h, xR + h)
int m = 0;
long long shift = -h, c = 0;
std::priority_queue<long long> pq_l;
std::priority_queue<long long, std::vector<long long>, std::greater<long long>> pq_r;
for (int i = 0; i < n; i++) {
long long x;
std::cin >> x;
// shift by h
shift += h;
c -= h * m;
// append to line
pq_l.push(x + shift);
pq_r.push(x - shift);
// normalize
while (true) {
long long x_l = pq_l.top();
long long x_r = pq_r.top();
if (x_l - shift <= x_r + shift) {
break;
}
pq_l.pop();
pq_r.pop();
x_l -= shift;
x_r += shift;
pq_l.push(x_r + shift);
pq_r.push(x_l - shift);
}
// m*x + c + (x - x0) = (m+1)*x + (c - x0)
m++;
c -= x;
}
while (!pq_r.empty()) {
// pop largest
long long x = pq_r.top();
pq_r.pop();
// apply shift
x += shift;
// m*x + c = (m-1)*x + (x + c)
m--;
c += x;
}
std::cout << c << std::endl;
return 0;
}
