#include <bits/stdc++.h>
template <typename T>
using minpq = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template <typename T>
struct SlopeTrick {
inline static const T inf = std::numeric_limits<int64_t>::max() / 2;
T cost = 0, left_offset = 0, right_offset = 0;
std::priority_queue<std::pair<T, T>> left;
minpq<std::pair<T, T>> right;
SlopeTrick() {
left.emplace(-inf, 0);
right.emplace(+inf, 0);
}
void add_left(T x, T slope) {
right.emplace(x - right_offset, slope);
while (slope > 0) {
auto [y, s] = right.top();
right.pop();
y += right_offset;
T take = std::min(slope, s);
cost += take * (x - y);
slope -= take;
s -= take;
left.emplace(y + left_offset, take);
if (s) {
right.emplace(y - right_offset, s);
}
}
}
void add_right(T x, T slope) {
left.emplace(x + left_offset, slope);
while (slope > 0) {
auto [y, s] = left.top();
left.pop();
y -= left_offset;
T take = std::min(slope, s);
cost += take * (y - x);
slope -= take;
s -= take;
right.emplace(y - right_offset, take);
if (s) {
left.emplace(y + left_offset, s);
}
}
}
void add_abs(T x, T slope) {
add_left(x, slope);
add_right(x, slope);
}
void relax_left(T offset) {
left_offset += offset;
}
void relax_right(T offset) {
right_offset += offset;
}
void relax(T offset) {
relax_left(offset);
relax_right(offset);
}
};
constexpr int64_t inf = std::numeric_limits<int64_t>::max() / 2;
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
int N, H;
std::cin >> N >> H;
std::vector<int> S(N);
for (int i = 0; i < N; ++i) {
std::cin >> S[i];
}
SlopeTrick<int64_t> st;
for (int i = 0; i < N; ++i) {
st.relax(H);
st.add_abs(S[i], 1);
}
std::cout << st.cost << '\n';
exit(0);
}
