#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>#include<cmath>using namespace std;const int N=1e6+5,INF=1e9;typedef long long ll;inline int read(){    char c=getchar();int x=0,f=1;    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1; c=getchar();}    while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘; 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)(2*a*(s[k]-s[j]));}int q[N],head,tail;void dp(){    head=tail=1;    for(int i=1;i<=n;i++){        while(head<tail&&slope(q[head],q[head+1])<=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-1],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=1;i<=n;i++) s[i]=s[i-1]+read();    dp();}