#include <bits/stdc++.h>
#define whlie while
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define rep(i,N) for(int i = 0; i < (N); i++)
#define repr(i,N) for(int i = (N) - 1; i >= 0; i--)
#define rep1(i,N) for(int i = 1; i <= (N) ; i++)
#define repr1(i,N) for(int i = (N) ; i > 0 ; i--)
#define each(x,v) for(auto& x : v)
#define all(v) (v).begin(),(v).end()
#define sz(v) ((int)(v).size())
#define vrep(v,it) for(auto it = v.begin(); it != v.end(); it++)
#define vrepr(v,it) for(auto it = v.rbegin(); it != v.rend(); it++)
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
using namespace std; void solve();
using ll = long long; using vl = vector<ll>;
using vi = vector<int>; using vvi = vector< vector<int> >;
constexpr int inf = 1001001001;
constexpr ll infLL = (1LL << 61) - 1;
struct IoSetupNya {IoSetupNya() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cerr << fixed << setprecision(7);} } iosetupnya;
template<typename T, typename U> inline bool amin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template<typename T, typename U> inline bool amax(T &x, U y) { return (x < y) ? (x = y, true) : false; }
template<typename T, typename U> ostream& operator <<(ostream& os, const pair<T, U> &p) { os << p.first << " " << p.second; return os; }
template<typename T, typename U> istream& operator >>(istream& is, pair<T, U> &p) { is >> p.first >> p.second; return is; }
template<typename T> ostream& operator <<(ostream& os, const vector<T> &v) { int s = (int)v.size(); rep(i,s) os << (i ? " " : "") << v[i]; return os; }
template<typename T> istream& operator >>(istream& is, vector<T> &v) { for(auto &x : v) is >> x; return is; }
void in(){} template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
void out(){cout << "\n";} template <typename T,class... U> void out(const T &t,const U &...u){ cout << t; if(sizeof...(u)) cout << " "; out(u...);}
template<typename T>void die(T x){out(x); exit(0);}
#ifdef NyaanDebug
  #include "NyaanDebug.h"
  #define trc(...) do { cerr << #__VA_ARGS__ << " = "; dbg_out(__VA_ARGS__);} while(0)
  #define trca(v,N) do { cerr << #v << " = "; array_out(v , N);cout << endl;} while(0)
#else
  #define trc(...)
  #define trca(...)
  int main(){solve();}
#endif

using P = pair<int,int>; using vp = vector<P>;
constexpr int MOD = /** 1000000007; //*/ 998244353;
////////////////


template<typename T , T INF>
struct DynamicLiChaoTree{
 
  struct Line{
    T slope , intercept;
    Line() : slope(0),intercept(INF){}
    Line(T slope,T intercept) : slope(slope),intercept(intercept){}
    inline T get(T x) const{
      return slope * x + intercept;
    }
    inline bool over(const Line& other , const T &x) const{
      return get(x) < other.get(x);
    }
  };
 
  // remind セグ木は0-indexedの実装
  T xmin, xmax, _size;
  unordered_map<T, Line> seg;
 
  // [l , r]におけるLi Chao Tree
  DynamicLiChaoTree(T xmin, T xmax) : xmin(xmin), xmax(xmax){
    _size = 1; while(_size < xmax - xmin + 1) _size <<= 1;
  }
 
  // y = ax + bなる直線を追加
  void update(T a, T b){ 
    Line line(a , b);
    T left = 0 , right = _size , seg_idx = 0;
    while(1){
      int mid = (left + right) >> 1;
      bool l_over = line.over(seg[seg_idx], min(xmax , left   + xmin) );
      bool r_over = line.over(seg[seg_idx], min(xmax , right-1+ xmin) );
      if(l_over == r_over){
        if(l_over) swap(seg[seg_idx] , line);
        return;
      }
      bool m_over = line.over(seg[seg_idx], min(xmax , mid + xmin) );
      if(m_over) swap(seg[seg_idx], line);
      if(l_over != m_over) seg_idx = 2 * seg_idx + 1 , right = mid;
      else seg_idx = 2 * seg_idx + 2 , left = mid;
    }
  }
 
  // xにおける最小値クエリ
  T query(T x) {
    T left = 0 , right = _size , seg_idx = 0 , idx = x - xmin , ret = INF;
    while(1){
      T cur = seg[seg_idx].get(x);
      if(cur == INF) break;
      ret = min(ret , cur);
      if(left + 1 >= right) break;
      int mid = (left + right) >> 1;
      if(idx < mid) seg_idx = seg_idx * 2 + 1 , right = mid;
      else seg_idx = seg_idx * 2 + 2 , left = mid; 
    }
    return ret;
  }
 
  void merge(DynamicLiChaoTree<T,INF> &other){
    if(seg.size() < other.seg.size()) seg.swap(other.seg);
    for(auto &x : other.seg){
      if(x.second.slope == 0 && x.second.intercept == INF) continue;
      update(x.second.slope , x.second.intercept);
    }
  }
 
};

void solve(){
  inl(N , C);
  vl h(N); in(h);
  vl dp(N , 0);
  DynamicLiChaoTree<ll , infLL> lichao(0 , 1000000);
  lichao.update(h[0] * (-2) , dp[0] + h[0] * h[0]);
  rep1(i , N - 1){
    dp[i] = lichao.query(h[i]) + h[i] * h[i] + C;
    lichao.update(h[i] * (-2) , dp[i] + h[i] * h[i]);
    trc(dp[i]);
  }
  out(dp[N - 1]);
}

Measured memory_bytes: 26100