#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#define DEBUG(...) debug(#__VA_ARGS__, __VA_ARGS__)
#else
#define DEBUG(...) 6
#endif
template<typename T, typename S> ostream& operator << (ostream &os, const pair<T, S> &p) {return os << "(" << p.first << ", " << p.second << ")";}
template<typename C, typename T = decay<decltype(*begin(declval<C>()))>, typename enable_if<!is_same<C, string>::value>::type* = nullptr>
ostream& operator << (ostream &os, const C &c) {bool f = true; os << "["; for (const auto &x : c) {if (!f) os << ", "; f = false; os << x;} return os << "]";}
template<typename T> void debug(string s, T x) {cerr << s << " = " << x << "\n";}
template<typename T, typename... Args> void debug(string s, T x, Args... args) {for (int i=0, b=0; i<(int)s.size(); i++) if (s[i] == '(' || s[i] == '{') b++; else
if (s[i] == ')' || s[i] == '}') b--; else if (s[i] == ',' && b == 0) {cerr << s.substr(0, i) << " = " << x << " | "; debug(s.substr(s.find_first_not_of(' ', i + 1)), args...); break;}}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, h;
cin >> n >> h;
priority_queue<long long> left;
priority_queue<long long, vector<long long>, greater<long long>> right;
long long ret = 0, llazy = 0, rlazy = 0;
for (int i=0; i<n; i++) {
int x;
cin >> x;
if (!left.empty() && x < left.top() + llazy) {
long long y = left.top() + llazy;
left.pop();
ret += y - x;
right.push(y - rlazy);
left.push(x - llazy);
left.push(x - llazy);
} else if (!right.empty() && x > right.top() + rlazy) {
long long y = right.top() + rlazy;
right.pop();
ret += x - y;
left.push(y - llazy);
right.push(x - rlazy);
right.push(x - rlazy);
} else {
left.push(x - llazy);
right.push(x - rlazy);
}
llazy -= h;
rlazy += h;
}
cout << ret << "\n";
return 0;
}
