using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	static void Main(){
		Sc sc=new Sc();
		var s=sc.La;
		var h=sc.La;
		var dp=new long[s[0]+1];
		var cht=new Lct(1,1000000,false);
		cht.Add(0,-h[0]*2,h[0]*h[0]);
		for(int i = 1;i<s[0];i++) {
			dp[i]=cht.Get(h[i]).Item2+h[i]*h[i]+s[1];
			cht.Add(i,-h[i]*2,dp[i]+h[i]*h[i]);
		}
		Console.WriteLine(dp[s[0]-1]);
	}
}
public class Lct{
	public class Dt{
		public int n;
		public long a,b;
		public Dt(int n,long a,long b){this.n=n;this.a=a;this.b=b;}
		public override string ToString()=>"n:"+n.ToString()+" a:"+a.ToString()+" b:"+b.ToString();
	}
	public class Nd{
		public readonly long nl,nr,nc;
		public Nd l,r;
		public Dt d;
		public Nd(long nl,long nr,Dt d){this.nl=nl;this.nr=nr;this.d=d;nc=(nr+nl+1)>>1;}
	}
	public Nd root;
	public Dt du;
	private Func<long,long,bool> co;
	private long p;
	public Lct(long nl,long nr,bool bo){
		root=new Nd(nl,nr,null);
		if(bo){co=Ao;p=long.MinValue;}
		else{co=Do;p=long.MaxValue;}
	}
	public void Add(int n,long a,long b){
		if(root.d==null){root.d=new Dt(n,a,b);}
		else{
			var t=root;
			var d=new Dt(n,a,b);
			while(true){
				bool bl=co(t.d.a*t.nl+t.d.b,d.a*t.nl+d.b);
				bool br=co(t.d.a*t.nr+t.d.b,d.a*t.nr+d.b);
				if(!bl&&!br){t.d=d;break;}
				else if(bl&&!br){
					if(co(t.d.a*t.nc+t.d.b,d.a*t.nc+d.b)){
						if(t.r==null){t.r=new Nd(t.nc,t.nr,d);break;}
						else{t=t.r;}
					}
					else{
						if(t.l==null){t.l=new Nd(t.nl,t.nc-1,t.d);t.d=d;break;}
						else{var e=d;d=t.d;t.d=e;t=t.l;}
					}
				}
				else if(!bl&&br){
					if(co(t.d.a*t.nc+t.d.b,d.a*t.nc+d.b)){
						if(t.l==null){t.l=new Nd(t.nl,t.nc-1,d);break;}
						else{t=t.l;}
					}
					else{
						if(t.r==null){t.r=new Nd(t.nc,t.nr,t.d);t.d=d;break;}
						else{var e=d;d=t.d;t.d=e;t=t.r;}
					}
				}
				else{break;}
			}
		}
	}
	public Tuple<int,long> Get(long n){
		var t=root;
		int f=0;
		long g=p;
		while(t!=null){
			if(co(t.d.a*n+t.d.b,g)){
				f=t.d.n;
				g=t.d.a*n+t.d.b;
			}
			t=n<t.nc?t.l:t.r;
		}
		return Tuple.Create(f,g);
	}
	private bool Ao(long x,long y){return x>=y;}
	private bool Do(long x,long y){return x<=y;}
}
public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),int.Parse);}
	public int[] Ia3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),long.Parse);}
	public long[] La3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),double.Parse);}
	public double[] Da3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}

Measured memory_bytes: 52824