// Marcin Knapik
#include<bits/stdc++.h>
 
#pragma GCC optimize("O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
 
using namespace std;
 
//#include <ext/pb_ds/assoc_container.hpp> // order_of_key
//#include <ext/pb_ds/tree_policy.hpp> // find by order
//using namespace __gnu_pbds; 
//#define ordered_set tree< int , null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>  
 
// const ll MAX_LL = 0xFFFFFFFFFFFFFFFF;
// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define losuj(a, b) uniform_int_distribution<ull>(a, b)(rng)
#define losuj_real(a, b) uniform_real_distribution<long double>(a, b)(rng)
 
typedef long double             ld;
typedef long long               ll;
typedef unsigned long long      ull;
typedef pair<ll, ll>            pll;
typedef pair<int, int>          ii;
typedef vector<int>             vi;
typedef vector<ii>              vii;
typedef vector<vi>              vvi;
typedef vector<vector<ii>>      vvii;
typedef vector< ll >            vll;
typedef vector< pll >           vpll;
 
#define sz(a)                   (int)(a).size()
#define pb                      push_back
#define all(c)                  (c).begin(), (c).end()
#define rall(c)                 (c).rbegin(), (c).rend()
#define FOR(i, a)               for (int i = 0; i < (a); i++)
#define f                       first
#define s                       second
#define rr "\e[31m "
#define bb "\e[m "
 
template <class T> inline bool setmin(T &a, T b){if (a > b)return a = b, 1;return 0;}
template <class T> inline bool setmax(T &a, T b){if (a < b)return a = b, 1;return 0;}
 
template<class T> inline  T fast(T a,T b,T mod) {ll res = 1; while(b){if(b&1) res = (res*a)%mod;a = (a*a)%mod;b >>= 1;}return res;}
template<class T> inline  T russian(T a, T b, T mod) {ll res = 0; while(b){if(b&1) res = (res + a)%mod; a = (a+a)%mod; b>>=1;}return res;}
template<class T> istream &operator>>(istream &os, vector<T> &container){for (auto &u : container)os >> u;return os;}
template<class T> ostream &operator<<(ostream &os, const vector<T> &container){for (auto &u : container)os << u << " ";return os;}
template<class T> inline  T gcd(T a, T b) { while (b)swap(a %= b, b); return a; }
 
const ll INF = 1e9 + 7;
const ll mod = 998244353;
const ll N = 1e6+7;
const ll T = 1<<20;
const ll BIG_INF = 1e18 + 7;
 
ll n, m, k;

ll dp[N];
ll h[N];

ii two_first(deque<int>&kol){
	int a = kol.front();
	kol.pop_front();
	int b = kol.front();
	kol.push_front(a);

	return {a, b};
}

ii two_last(deque<int>&kol){
	int a = kol.back();
	kol.pop_back();
	int b = kol.back();
	kol.push_back(a);

	return {a, b};
}

ll get_val(int star, int nowy){
	return dp[star] + (h[nowy] - h[star]) * (h[nowy] - h[star]) + m; 
}

int overtakes(int lepszy, int gorszy){
	if(get_val(gorszy, n-1) < get_val(lepszy, n-1))
		return INF;
	int L = lepszy-1, P = n-1;

	while(P - L > 1){
		int mid = (P + L) / 2;
		(get_val(gorszy, mid) >= get_val(lepszy, mid) ? P : L) = mid;
	}
	return P;
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);

	cin >> n >> m;

	FOR(i, n)
		cin >> h[i];

	deque<int> kolejka;
	kolejka.pb(0);

	for(int i = 1; i < n; i++){
		if(sz(kolejka) >= 2){
			ii pom = two_first(kolejka);
			if(overtakes(pom.s, pom.f) <= i)
				kolejka.pop_front();
		}
		dp[i] = get_val(kolejka.front(), i);
		while(sz(kolejka) >= 2){
			ii pom = two_last(kolejka);
			if(overtakes(i, pom.f) <= overtakes(pom.f, pom.s))
				kolejka.pop_back();
			else
				break;
		}
		kolejka.push_back(i);
	}
	cout << dp[n-1] << '\n';
}	

Measured memory_bytes: 6016