#include<iostream>

 #include<cstdio>

 #include<cstdlib>

 #include<cstring>

 #include<ctime>

 #include<cmath>

 #include<algorithm>

 using namespace std;

 typedef long long ll;

 #define MAXN 1000100

 #define FILE "read"

 #define up(i,j,n) for(ll i=j;i<=n;i++)

 ll n,a,b,c,l,r,x[MAXN],sum[MAXN],q[MAXN],f[MAXN];

 namespace INIT{

     char buf[<<],*fs,*ft;

     inline char getc() {return (fs==ft&&(ft=(fs=buf)+fread(buf,,<<,stdin),fs==ft))?:*fs++;}

     inline ll read() {

         ll x=,f=;  char ch=getc();

         while(!isdigit(ch))  {if(ch=='-')  f=-;  ch=getc();}

         while(isdigit(ch))  {x=x*+ch-'';  ch=getc();}

         return x*f;

     }

 }using namespace INIT;

 inline double slop(ll j,ll k) {return (double)((f[j]+a*sum[j]*sum[j]-b*sum[j])-(f[k]+a*sum[k]*sum[k]-b*sum[k]))/(double)(sum[j]-sum[k]);}

 int main(){

     freopen(FILE".in","r",stdin);

     freopen(FILE".out","w",stdout);

     n=read();  a=read();  b=read();  c=read();

     up(i,,n) x[i]=read(),sum[i]=sum[i-]+x[i];

     up(i,,n){

         while(l<r&&slop(q[l],q[l+])>*a*sum[i])  l++;

         ll t=q[l];

         f[i]=f[t]+a*(sum[i]-sum[t])*(sum[i]-sum[t])+b*(sum[i]-sum[t])+c;

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

         q[++r]=i;

     }

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

     return ;

 }