#include<iostream>

#include<cstring>

#include<algorithm>

#include<cstdio>

#define Maxn 1000010

#define LL unsigned __int64

using namespace std;

LL dp[Maxn],num[Maxn];

int que[Maxn*];

inline int ReadInt()

{

     char ch = getchar();

     int data = ;

     while (ch < '' || ch > '')

         ch = getchar();

     do

     {

         data = data* + ch-'';

         ch = getchar();

     } while (ch >= '' && ch <= '');

     return data;

 }

int main()

{

    int n,i,j;

    LL c;

    while(scanf("%d%I64u",&n,&c)!=EOF,n||c){

        memset(dp,,sizeof(dp));

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

            num[i]=(LL)ReadInt();

        int head,rear;

        head=;rear=;

        que[++rear]=;

        dp[]=;

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

            while(head<rear&&(dp[que[head+]]+num[que[head+]+]*num[que[head+]+]-(dp[que[head]]+num[que[head]+]*num[que[head]+])<=*num[i]*(num[que[head+]+]-num[que[head]+])))

                head++;

            dp[i]=dp[que[head]]+(num[i]-num[que[head]+])*(num[i]-num[que[head]+])+c;

            while(head<rear&&(dp[i]+num[i+]*num[i+]-(dp[que[rear]]+num[que[rear]+]*num[que[rear]+]))*(num[que[rear]+]-num[que[rear-]+])<=(dp[que[rear]]+num[que[rear]+]*num[que[rear]+]-(dp[que[rear-]]+num[que[rear-]+]*num[que[rear-]+]))*(num[i+]-num[que[rear]+]))

                rear--;

            que[++rear]=i;

        }

        printf("%I64u\n",dp[n]);

    }

    return ;

}