//SLOPE TRICK, MUITO LEGAL
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#ifndef LOCAL
#define debug(...) (void)0
#endif
using namespace std;
namespace __gnu_pbds {
template<typename T>
using ordered_set = tree<
T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
}
using __gnu_pbds::ordered_set;
using int128 = __int128;
template<typename T>
bool maximize(T& target, const T& value)
{ return target < value ? (target = value, true) : false; }
template<typename T>
bool minimize(T& target, const T& value)
{ return target > value ? (target = value, true) : false; }
istream& operator>>(istream& is, int128& x)
{ long long y; is >> y, x = y; return is; }
ostream& operator<<(ostream& os, const int128& x)
{ assert(x >= LONG_LONG_MIN && x <= LONG_LONG_MAX); return os << (long long)x; }
const int inf = 0x3f3f3f3f;
const long long linf = 0x3f3f3f3f3f3f3f3f;
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
int main() {
int n, h;
cin >> n >> h;
priority_queue<long long> left;
priority_queue<long long, vector<long long>, greater<long long>> right;
long long dl = 0, dr = 0;
long long ans = 0;
for (int i = 0; i < n; ++i) {
int a;
cin >> a;
if (i == 0) {
left.push(a);
right.push(a);
continue;
}
dl -= h, dr += h;
if (a < left.top() + dl) {
ans += left.top() + dl - a;
left.push(a - dl);
left.push(a - dl);
right.push(left.top() + dl - dr);
left.pop();
} else if (a > right.top() + dr) {
ans += a - (right.top() + dr);
right.push(a - dr);
right.push(a - dr);
left.push(right.top() + dr - dl);
right.pop();
} else {
left.push(a - dl);
right.push(a - dr);
}
}
cout << ans << '\n';
return 0;
}
