#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
const int N=5e5+10;
typedef long long ll;
inline int read() {
	int s = 0, t = 1; char c = getchar();
	while( !isdigit(c) ) { if( c == '-' ) t = -1; c = getchar(); }
	while( isdigit(c) ) s = s * 10 + c - 48, c = getchar();
	return s * t;  
}

int n, head, tail;
ll sum[N], Sum[N], a[N], ans;
struct node{
	ll x,y;
	node(ll X=0,ll Y=0){x=X;y=Y;}
	node operator - (node a){return node(x-a.x,y-a.y);}
	__int128 operator * (node a){return (__int128)x*a.y-(__int128)y*a.x;}
}p[N],q[N],Q[N],A[N];
ll calc(node p,node q){return p.x*q.x+p.y+q.y;}
bool cmp(node x,node y){return x.x<y.x;}
void solve(int l,int r){
	if (l==r) return;
	int mid=(l+r)>>1;
	solve(l,mid);
	solve(mid+1,r);
	head=1;tail=0;
	for (int i=l;i<=mid;i++){
		for (;tail>1&&(Q[tail]-Q[tail-1])*(p[i]-Q[tail])>0;tail--);
		Q[++tail]=p[i];
	}
	for (int i=mid+1;i<=r;i++){
		for (;head<tail&&calc(q[i],Q[head])<calc(q[i],Q[head+1]);head++);
		ll val=-1e18;
		for (int j=l;j<=mid;j++) val=max(val,calc(q[i],p[j]));
		ans=max(ans,calc(q[i],Q[head]));
	}
	merge(p+l,p+mid+1,p+mid+1,p+r+1,A+l,cmp);
	for (int i=l;i<=r;i++) p[i]=A[i];
	merge(q+l,q+mid+1,q+mid+1,q+r+1,A+l,cmp);
	for (int i=l;i<=r;i++) q[i]=A[i];
}
int main()
{
	n = read();
	for (int i=1;i<=n;i++) a[i] = read();
	for (int i=1;i<=n;i++) sum[i]=sum[i-1]+a[i];
	for (int i=1;i<=n;i++) Sum[i]=Sum[i-1]+a[i]*a[i];
	for (int i=0;i<n;i++) p[i]=node(sum[i],sum[i]*sum[i]+Sum[i]);
	for (int i=1;i<=n;i++) q[i]=node(-2*sum[i],sum[i]*sum[i]-Sum[i]);
	solve(0,n);
	cout<<ans/2<<endl;
	return 0;
}