#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
const int oo=0x3f3f3f3f;
using namespace std;
int a[100010],dp[100010][110],x[110];
int f(int q){
return q*q;
}
int main(){
//freopen("telewire.in","r",stdin);
//freopen("telewire.out","w",stdout);
int i,j,k,m,n,c;
scanf("%d%d",&n,&c);
for(i=1;i<=n;i++)
scanf("%d",&a[i]);
memset(dp,oo,sizeof(dp));
for(i=0;i<=100;i++)
x[i]=f(i);
for(i=a[1];i<=100;i++)
dp[1][i]=x[i-a[1]];
for(i=2;i<=n;i++)
for(k=a[i];k<=100;k++)
for(j=a[i-1];j<=100;j++)
if(dp[i][k]>dp[i-1][j]+x[k-a[i]]+abs(k-j)*c)
dp[i][k]=dp[i-1][j]+x[k-a[i]]+abs(k-j)*c;
int ans=oo;
for(int i=a[n];i<=100;i++)
if(ans>dp[n][i])ans=dp[n][i];
printf("%d\n",ans);
return 0;
}
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
const int oo=0x3f3f3f3f;
using namespace std;
int a[100010],dp[100010][110],x[110];
int f(int q){
return q*q;
}
int main(){
//freopen("telewire.in","r",stdin);
//freopen("telewire.out","w",stdout);
int i,j,k,m,n,c;
scanf("%d%d",&n,&c);
for(i=1;i<=n;i++)
scanf("%d",&a[i]);
memset(dp,oo,sizeof(dp));
for(i=0;i<=100;i++)
x[i]=f(i);
for(i=a[1];i<=100;i++)
dp[1][i]=x[i-a[1]];
for(i=2;i<=n;i++)
for(k=a[i];k<=100;k++)
for(j=a[i-1];j<=100;j++)
if(dp[i][k]>dp[i-1][j]+x[k-a[i]]+abs(k-j)*c)
dp[i][k]=dp[i-1][j]+x[k-a[i]]+abs(k-j)*c;
int ans=oo;
for(int i=a[n];i<=100;i++)
if(ans>dp[n][i])ans=dp[n][i];
printf("%d\n",ans);
return 0;
}