#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

#include<cmath>

using namespace std;

const int N=1e6+,INF=1e9;

typedef long long ll;

inline int read(){

    char c=getchar();int x=,f=;

    while(c<''||c>''){if(c=='-')f=-; c=getchar();}

    while(c>=''&&c<=''){x=x*+c-''; c=getchar();}

    return x*f;

}

int n,a,b,c;

ll s[N],f[N];

inline double slope(int j,int k){

    return  (double)(a*(s[k]*s[k]-s[j]*s[j])+f[k]-f[j]+b*(s[j]-s[k]))/(double)(*a*(s[k]-s[j]));

}

int q[N],head,tail;

void dp(){

    head=tail=;

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

        while(head<tail&&slope(q[head],q[head+])<=s[i]) head++;

        int j=q[head];

        f[i]=f[j]+a*(s[i]-s[j])*(s[i]-s[j])+b*(s[i]-s[j])+c;//printf("f %lld %d\n",f[i],j);

        while(head<tail&&slope(q[tail-],q[tail])>slope(q[tail],i)) tail--;

        q[++tail]=i;

    }

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

}

int main(){

    //freopen("in.txt","r",stdin);

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

    for(int i=;i<=n;i++) s[i]=s[i-]+read();

    dp();

}