#define IOS ios_base::sync_with_stdio(0); cin.tie(0);

 #include <cstdio>//sprintf islower isupper

 #include <cstdlib>//malloc  exit strcat itoa system("cls")

 #include <iostream>//pair

 #include <fstream>//freopen("C:\\Users\\13606\\Desktop\\Input.txt","r",stdin);

 #include <bitset>

 //#include <map>

 //#include<unordered_map>

 #include <vector>

 #include <stack>

 #include <set>

 #include <string.h>//strstr substr strcat

 #include <string>

 #include <time.h>// srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;

 #include <cmath>

 #include <deque>

 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less

 #include <vector>//emplace_back

 //#include <math.h>

 #include <cassert>

 #include <iomanip>

 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor

 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)

 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation

 //******************

 clock_t __START,__END;

 double __TOTALTIME;

 void _MS(){__START=clock();}

 void _ME(){__END=clock();__TOTALTIME=(double)(__END-__START)/CLOCKS_PER_SEC;cout<<"Time: "<<__TOTALTIME<<" s"<<endl;}

 //***********************

 #define rint register int

 #define fo(a,b,c) for(rint a=b;a<=c;++a)

 #define fr(a,b,c) for(rint a=b;a>=c;--a)

 #define mem(a,b) memset(a,b,sizeof(a))

 #define pr printf

 #define sc scanf

 #define ls rt<<1

 #define rs rt<<1|1

 typedef pair<int,int> PII;

 typedef vector<int> VI;

 typedef unsigned long long ull;

 typedef long long ll;

 typedef double db;

 const double E=2.718281828;

 const double PI=acos(-1.0);

 const ll INF=(1LL<<);

 const int inf=(<<);

 const double ESP=1e-;

 const int mod=(int)1e9+;

 const int N=(int)1e6+;

 int n,L;

 int a[N];

 db dp[N],sum[N];

 db A(int x)

 {

     return sum[x]+x;

 }

 db B(int x)

 {

     return sum[x]+x+L+;

 }

 db X(int x)

 {

     return B(x);

 }

 db Y(int x)

 {

     return dp[x]+B(x)*B(x);

 }

 double slope(int a,int b)

 {

     return 1.0*(Y(a)-Y(b))/(1.0*(X(a)-X(b)));

 }

 class mydeque{

 public:

     int len=;

     int p[N];

     int l,r,tot;

     void init()

     {

         l=;r=;

         tot=;

     }

     int size()

     {

         return tot;

     }

     int pos(int x)

     {

         return (x+len)%len;

     }

     int f()

     {

         return p[l];

     }

     int b()

     {

         return p[r];

     }

     void pf(int x)

     {

         tot++;

         l=pos(l-);

         p[l]=x;

     }

     void pb(int x)

     {

         tot++;

         r=pos(r+);

         p[r]=x;

     }

     void popf()

     {

         p[l]=;

         l=pos(l+);

         tot--;

     }

     void popb()

     {

         p[r]=;

         r=pos(r-);

         tot--;

     }

 }q;

 int main()

 {

     q.init();//初始化有dp[0](l=r=1而不是l=1,r=0,tot=0),因为要用到

     sc("%d%d",&n,&L);

     for(int i=;i<=n;++i)sc("%d",&a[i]),sum[i]=a[i]+sum[i-];

     for(int i=;i<=n;++i)

     {

         while(q.l<q.r&&slope(q.f(),q.p[q.pos(q.l+)])<2.0*A(i))q.popf();

         dp[i]=dp[q.f()]+(A(i)-B(q.f()))*(A(i)-B(q.f()));

         while(q.l<q.r&&slope(q.p[q.pos(q.r-)],q.b())>slope(q.p[q.pos(q.r-)],i))q.popb();

         q.pb(i);

     }

     pr("%lld\n",(ll)dp[n]);

     return ;

 }

 /**************************************************************************************/