#include<iostream> #include<cstdio> #include<queue> using namespace std; inline int read(){ int x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return f*x; } int n,a,b,c,x,q[1000005],l,r; long long sum[1000005],f[1000005]; inline long long sqr(long long x){return x*x;} inline double calc(int k,int j){ return (double)(f[j]-f[k]+a*(sqr(sum[j])-sqr(sum[k]))+b*(sum[k]-sum[j]))/(double)(2*a*(sum[j]-sum[k])); } int main(){ n=read();a=read();b=read();c=read(); for(int i=1;i<=n;i++){ x=read();sum[i]=sum[i-1]+(long long)x; } for(int i=1;i<=n;i++){ while(l<r&&calc(q[l],q[l+1])<sum[i])l++; int t=q[l]; f[i]=f[t]+a*sqr(sum[i]-sum[t])+b*(sum[i]-sum[t])+c; while(l<r&&calc(q[r-1],q[r])>calc(q[r],i))r--; q[++r]=i; } printf("%lld",f[n]); return 0; }