#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair 
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 

template<class T> bool ckmin(T& a, const T& b) { 
	return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
	return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bit(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 

namespace input {
	template<class T> void re(complex<T>& x);
	template<class T1, class T2> void re(pair<T1,T2>& p);
	template<class T> void re(vector<T>& a);
	template<class T, size_t SZ> void re(array<T,SZ>& a);

	template<class T> void re(T& x) { cin >> x; }
	void re(double& x) { string t; re(t); x = stod(t); }
	void re(ld& x) { string t; re(t); x = stold(t); }
	template<class T, class... Ts> void re(T& t, Ts&... ts) { 
		re(t); re(ts...); 
	}

	template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = {a,b}; }
	template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
	template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
	template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}

using namespace input;

namespace output {
	void pr(int x) { cout << x; }
	void pr(long x) { cout << x; }
	void pr(ll x) { cout << x; }
	void pr(unsigned x) { cout << x; }
	void pr(unsigned long x) { cout << x; }
	void pr(unsigned long long x) { cout << x; }
	void pr(float x) { cout << x; }
	void pr(double x) { cout << x; }
	void pr(ld x) { cout << x; }
	void pr(char x) { cout << x; }
	void pr(const char* x) { cout << x; }
	void pr(const string& x) { cout << x; }
	void pr(bool x) { pr(x ? "true" : "false"); }
	template<class T> void pr(const complex<T>& x) { cout << x; }
	
	template<class T1, class T2> void pr(const pair<T1,T2>& x);
	template<class T> void pr(const T& x);
	
	template<class T, class... Ts> void pr(const T& t, const Ts&... ts) { 
		pr(t); pr(ts...); 
	}
	template<class T1, class T2> void pr(const pair<T1,T2>& x) { 
		pr("{",x.f,", ",x.s,"}"); 
	}
	template<class T> void pr(const T& x) { 
		pr("{"); // const iterator needed for vector<bool>
		bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; 
		pr("}");
	}
	
	void ps() { pr("\n"); } // print w/ spaces
	template<class T, class... Ts> void ps(const T& t, const Ts&... ts) { 
		pr(t); if (sizeof...(ts)) pr(" "); ps(ts...); 
	}
	
	void pc() { pr("]\n"); } // debug w/ commas
	template<class T, class... Ts> void pc(const T& t, const Ts&... ts) { 
		pr(t); if (sizeof...(ts)) pr(", "); pc(ts...); 
	}
	#define dbg(x...) pr("[",#x,"] = ["), pc(x);
}

using namespace output;

namespace io {
	void setIn(string s) { freopen(s.c_str(),"r",stdin); }
	void setOut(string s) { freopen(s.c_str(),"w",stdout); }
	void setIO(string s = "") {
		ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
		// cin.exceptions(cin.failbit); 
		// throws exception when do smth illegal
		// ex. try to read letter into int
		if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
	}
}

using namespace io;

mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 



/**
 * Description: LineContainer; add lines of the form $kx+m$, 
 	* compute greatest $y$-coordinate for any $x$.
 * Time: O(\log N)
 * Source: KACTL
   * https://github.com/kth-competitive-programming/kactl/commit/165807e28402c9be906f6e6a09452431787bb70d?diff=unified
 * Verification: 
   * CSA Squared Ends not working :(
   * https://codeforces.com/contest/1083/problem/E
   * https://atcoder.jp/contests/arc066/tasks/arc066_d
 */

bool Q;
struct Line {
	mutable ll k, m, p; // slope, y-intercept, last optimal x
	ll eval (ll x) { return k*x+m; }
	bool operator<(const Line& o) const { return Q?p<o.p:k<o.k; }
};

// for doubles, use inf = 1/.0, divi(a,b) = a/b
const ll inf = LLONG_MAX;
// floored div
ll divi(ll a, ll b) { return a/b-((a^b) < 0 && a%b); } 
// last x such that first line is better
ll bet(const Line& x, const Line& y) { 
	if (x.k == y.k) return x.m >= y.m ? inf : -inf;
	return divi(y.m-x.m,x.k-y.k); }

struct LC : multiset<Line> { 
	// updates x->p, determines if y is unneeded
	bool isect(iterator x, iterator y) { 
		if (y == end()) { x->p = inf; return 0; }
		x->p = bet(*x,*y); return x->p >= y->p; }
	void add(ll k, ll m) {
		auto z = insert({k,m,0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p) 
			isect(x, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		Q = 1; auto l = *lb({0,0,x}); Q = 0;
		return l.k*x+l.m;
	}
};

struct LCdeque : deque<Line> { 
	void addBack(Line L) { // assume nonempty
		while (1) {
			auto a = bk; pop_back(); a.p = bet(a,L);
			if (size() && bk.p >= a.p) continue;
			pb(a); break;
		}
		L.p = inf; pb(L);
	}
	void addFront(Line L) {
		while (1) {
			if (!size()) { L.p = inf; break; }
			if ((L.p = bet(L,ft)) >= ft.p) pop_front();
			else break;
		}
		push_front(L);
	}
	void add(ll k, ll m) { // line goes to one end of deque
		if (!size() || k <= ft.k) addFront({k,m,0});
		else assert(k >= bk.k), addBack({k,m,0});
	}
	int ord = 0; // 1 = increasing, -1 = decreasing
	ll query(ll x) { 
		assert(ord);
		if (ord == 1) { 
			while (ft.p < x) pop_front();
			return ft.eval(x);
		} else {
			while(size()>1&&prev(prev(end()))->p>=x)pop_back();
			return bk.eval(x);
		}
	}	
};

ll h[200005];
ll dp[200005];
int main() {
	setIO();
	LCdeque lins;
	lins.ord = 1;
	int N;
	ll C;
	cin >> N >> C;
	for(int i = 1; i <= N; i++){
		cin >> h[i];
	}
	lins.add(2*h[1], -(0+h[1]*h[1]));
	for(int i = 2; i <= N; i++){
		ll val = lins.query(h[i]);
		val*=-1;
		val+=h[i]*h[i]+C;
		dp[i] = val;
		lins.add(2*h[i], -(val+h[i]*h[i]));
		//if(i == 3) ps(2*h[i], -(val+h[i]*h[i]));
	}
	ps(dp[N]);
	// you should actually read the stuff at the bottom
}

/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
*/

Measured memory_bytes: 6656