#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep3(i, l, n) for (int i = l; i < (n); ++i)
#define sz(v) (int)v.size()
const int inf = 1e9 + 7;
const ll INF = 1e18;
const int mod = 1000000007;
#define abs(x) (x >= 0 ? x : -(x))
#define lb(v, x) (int)(lower_bound(all(v), x) - v.begin())
#define ub(v, x) (int)(upper_bound(all(v), x) - v.begin())
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { if (a < b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a, T b) { if (b == 0) return a; return gcd(b, a % b); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
template<typename T> T pow(T a, int b) { return b ? pow(a * a, b / 2) * (b % 2 ? a : 1) : 1; }
ll modpow(ll a, int b, int _mod) { return b ? modpow(a * a % _mod, b / 2, _mod) * (b % 2 ? a : 1) % _mod : 1; }
template<class T> ostream& operator<<(ostream& os, const vector<T>& vec) { for (auto &vi: vec) os << vi << " "; return os; }
template<class T, class U> ostream& operator<<(ostream& os, const pair<T, U>& p) { os << p.F << " " << p.S; return os; }
template<typename T >inline istream& operator >> (istream& is, vector<T>& v) { rep(j, sz(v)) is >> v[j]; return is; }
template<class T> inline void add(T &a, int b) { a += b; if (a >= mod) a -= mod; }



void solve();

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(10);

    int T;
    // cin >> T;
    T = 1;

    while (T--) {
        solve();
    }
}



// https://kyopro-friends.hatenablog.com/entry/2019/01/12/231106
// https://atcoder.jp/contests/dp/submissions/3944283
int n;
ll c;
vector<ll> a;
vector<ll> dp;

ll A(int j) { return -2 * a[j]; }
ll B(int j) { return dp[j] + a[j] * a[j]; }
ll C(int i) { return a[i] * a[i] + c; }
// 直線 f_j の x における値
ll f(int j, int x) { return A(j) * x + B(j); }
// f2 が最小値をとる可能性がないか
// ない, 1
bool check(int f1, int f2, int f3) {
  ll a1 = A(f1), b1 = B(f1);
  ll a2 = A(f2), b2 = B(f2);
  ll a3 = A(f3), b3 = B(f3);
  return (a2 - a3) * (b1 - b2) >= (b2 - b3) * (a1 - a2);
}

void solve() {
  cin >> n >> c;
  a.resize(n);
  cin >> a;

  // 足場 i にたどり着くまでの最小コスト
  dp = vector<ll>(n);
  dp[0] = 0;

  deque<int> deq; // index を入れる
  deq.push_back(0);

  rep3(i, 1, n) {
    // 先頭が最小値になるまで
    auto get = [&](int x) {
      // rep(i, sz(deq)) cout << deq[i] << " "; cout << endl;
      while (sz(deq) >= 2) { // s1, s2
        int s1 = deq.front();
        deq.pop_front();
        int s2 = deq.front();
        if (f(s1, x) <= f(s2, x)) { // s1 が最小値
          deq.push_front(s1);
          break;
        }
      }
      return f(deq[0], x);
    };
    dp[i] = get(a[i]) + C(i);

    // 最小値になる可能性がないのを後ろから消す
    auto add = [&](int x) {
      while (sz(deq) >= 2) { // l2, l1, i
        int l1 = deq.back();
        deq.pop_back();
        int l2 = deq.back();
        // l1 は最小値にならない
        // debuged, check が 1 のときかい, 永遠に事故ってた
        if (check(l2, l1, x)) { 
          deq.push_back(l1);
          break;
        }
      }
      deq.push_back(x);
    };
    add(i);
  }
  cout << dp[n - 1] << endl;
}


Measured memory_bytes: 3968