1 #include <iostream>
 2 #include <stdio.h>
 3 #include <algorithm>
 4 #include <string.h>
 5 #include <set>
 6 using namespace std;
 7 int a[600000],sum[600000],h[600000],dp[600000],m;
 8 int getup(int j,int k)
 9 {
10     return dp[j]+sum[j]*sum[j]-dp[k]-sum[k]*sum[k];
11 }
12 int getdown(int j,int k)
13 {
14     return ((sum[j]-sum[k])<<1);
15 }
16 int getdp(int i,int j)
17 {
18     return dp[j]+m+(sum[i]-sum[j])*(sum[i]-sum[j]);
19 }
20 int main()
21 {
22     int n,i,head,tail;
23     while(~scanf("%d%d",&n,&m))
24     {
25         memset(h,0,sizeof(h));
26         sum[0]=a[0]=0;
27         for(i=1; i<=n; i++)
28             scanf("%d",&a[i]),sum[i]=sum[i-1]+a[i];
29             head=tail=0;
30             h[tail++]=0;
31         for(i=1;i<=n;i++)
32         {
33             while(head+1<tail&&getup(h[head+1],h[head])<=sum[i]*getdown(h[head+1],h[head]))
34             head++;
35             dp[i]=getdp(i,h[head]);
36             while(head+1<tail&&getup(h[tail-1],h[tail-2])*getdown(i,h[tail-1])>=getup(i,h[tail-1])*getdown(h[tail-1],h[tail-2]))
37             tail--;
38             h[tail++]=i;
39         }
40         cout<<dp[i-1]<<endl;
41     }
42 }