ll s;
void f(ll h,ll d[1<<20],ll&n){
	n=1;
	d[0]=0;
	rep(i,h){
		ll@a;
		s+=a;
		REP(j,n){
			d[n++]=d[j]+a+(1ll<<54);
		}
	}
}
{
	ll@n;
	ll h=n/2;
	ll ad[1<<20],an;
	ll bd[1<<20],bn;
	f(h,ad,an);
	sortA(an,ad);
	f(h,bd,bn);
	sortA(bn,bd);
	ll z=ll_inf;
	ll ai=0,bi=bn-1;
	while(ai<an&&bi>=0){
		ll e=ad[ai]+bd[bi];
		if(e>>54<h){
			++ai;
		}else if(e>>54>h){
			--bi;
		}else{
			ll c=(e&~(~0ll<<54))*2-s;
			z<?=abs(c);
			if(c<0){
				++ai;
			}else{
				--bi;
			}
		}
	}
	wt(z);
}