// TranThienPhuc2657
#include <bits/stdc++.h>
using namespace std;
#define file "lehoi"
#define TIME 1.0 * clock() / CLOCKS_PER_SEC
#define ll long long
#define pb push_back
#define fi first
#define se second
#define pii pair <int, int>
#define pll pair <ll, ll>
#define ld long double
#define Sz(x) ((int) (x).size())
#define getBit(mask, i) (((mask) >> (i)) & 1)
template <typename T1, typename T2> bool mini(T1 &A, T2 B) {if (A > B) A = B; else return 0; return 1;}
template <typename T1, typename T2> bool maxi(T1 &A, T2 B) {if (A < B) A = B; else return 0; return 1;}
const int inf = 2e9 + 7;
const ll linf = 1e18l + 7;
const int mod = 1e9 + 7;
const int N = 2e5 + 5;

int n, k, a[N];
ll pref[N], dp[N];

// init
void init() {
    for (int i = 1; i <= n; i++) pref[i] = pref[i - 1] + a[i];
    memset(dp, 0x3f, (n + 5) * sizeof(ll));
    dp[0] = 0;
}

// inp
void inp() {
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];
}

// proc
ll cost(int l, int r) {
    int mid = (l + r) / 2;
    return 1ll * (mid - l + 1) * a[mid] - (pref[mid] - pref[l - 1]) + (pref[r] - pref[mid]) - 1ll * (r - (mid + 1) + 1) * a[mid] + k;
}

void dnc(int l, int r, int optl, int optr) {
    if (l > r) return;
    int mid = (l + r) / 2;
    dnc(l, mid - 1, optl, optr);
    int opt = 0;
    for (int j = optl; j <= min(optr, mid - 1); j++) {
        if (mini(dp[mid], dp[j] + cost(j + 1, mid))) opt = j;
    }
    dnc(mid + 1, r, opt, optr);
}

void proc() {
    dnc(1, n, 0, n);
    cout << dp[n];
}

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(file".inp", "r")) {
        freopen(file".inp", "r", stdin);
        freopen(file".out", "w", stdout);
    }

    inp();
    init();
    proc();
    cerr << "Time elapsed: " << TIME << "s.\n";
    return 0;
}