#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <math.h>
#define rep(i, s, e) for (ll i = s; i < e; i++)
#define upmax(a, b) a = max(a, b)
#define upmin(a, b) a = min(a, b)
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using vvpll = vector<vpll>;
const ll INF = 1e18;
const ll MOD = 1e9 + 7;
//const ll MAX_H = 5005;
void solve() {
ll n, H;
cin >> n >> H;
vll arr(n);
rep(i, 0, n) cin >> arr[i];
ll MAX_H = 2 * (*(max_element(arr.begin(), arr.end())));
vvll dp(n, vll(MAX_H, INF));
rep(j, 0, MAX_H) {
dp[0][j] = abs(arr[0] - j);
}
rep(i, 1, n) {
rep(j, 0, MAX_H) {
rep(k, max(j - H, (ll)0), min(MAX_H, j + H + 1)) {
upmin(dp[i][j], dp[i - 1][k] + abs(arr[i] - j));
}
}
}
ll res = INF;
rep(j, 0, MAX_H) upmin(res, dp[n - 1][j]);
cout << res << endl;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
}
