#include<iostream>
#include<cstdio>
#include<cstring>
#define mysister
#define maxn 2501
using namespace std;
int n,m,a[maxn],f[maxn],ans=0x7fffffff;
int main()
{
	freopen("cowriver.in","r",stdin);
	freopen("cowriver.out","w",stdout);
	scanf("%d%d",&n,&m);
	memset(f,0x7f,sizeof(f));
	for(int i=1;i<=n;i++)
	{
	  scanf("%d",&a[i]);
	  a[i]+=a[i-1];
	  f[i]=a[i]+m;
	}
	for(int j=1;j<=n;j++)
	  for(int k=1;k<=j;k++)
		f[j]=min(f[j],f[k]+a[j-k]+2*m);
	printf("%d",f[n]);
	return 0;
}