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

     Problem: 1010

     User: Tunix

     Language: C++

     Result: Accepted

     Time:132 ms

     Memory:2640 kb

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

 //BZOJ 1010

 #include<cmath>

 #include<vector>

 #include<cstdio>

 #include<cstring>

 #include<cstdlib>

 #include<iostream>

 #include<algorithm>

 #define rep(i,n) for(int i=0;i<n;++i)

 #define F(i,j,n) for(int i=j;i<=n;++i)

 #define D(i,j,n) for(int i=j;i>=n;--i)

 #define pb push_back

 using namespace std;

 int getint(){

     int v=,sign=; char ch=getchar();

     while(ch<''||ch>''){ if (ch=='-') sign=-; ch=getchar();}

     while(ch>=''&&ch<=''){ v=v*+ch-''; ch=getchar();}

     return v*=sign;

 }

 const int N=;

 typedef long long LL;

 /******************tamplate*********************/

 LL c[N],s[N],f[N];

 int q[N],l,r;

 double slop(int k,int j){

     return double(f[j]+s[j]*s[j]-f[k]-s[k]*s[k])/

         double(*(s[j]-s[k]));

 }

 int main(){

     int n=getint(),L=getint()+;

     F(i,,n){

         c[i]=getint()+;

         s[i]=s[i-]+c[i];

     }

     F(i,,n){

         while(l<r && slop(q[l],q[l+])<s[i]-L) l++;

         int t=q[l];

         f[i]=f[t]+(s[i]-s[t]-L)*(s[i]-s[t]-L);

         while(l<r && slop(q[r-],q[r])>slop(q[r],i))r--;

         q[++r]=i;

     }

     printf("%lld\n",f[n]);

     return ;

 }