ll@n,@a[n],xl[n],yl[n],mi,ma,x,y,s,z=-ll_inf;
mi=ma=0,x=-ll_inf,y=ll_inf,s=0;
rep(i,n){
	s+=a[i];
	xl[i]=x>?=s-mi;
	yl[i]=y<?=s-ma;
	mi<?=s;
	ma>?=s;
}
mi=ma=0,x=-ll_inf,y=ll_inf,s=0;
rrep(i,1,n){
	s+=a[i];
	x>?=s-mi;
	y<?=s-ma;
	z>?=xl[i-1]*x;
	z>?=yl[i-1]*y;
	mi<?=s;
	ma>?=s;
}
wt(z);