ll@n,@a[n],@b[n],c[n];
rep(i,n){
	if(a[i]<0){
		a[i]=-a[i];
		b[i]=-b[i];
	}
	c[i]=a[i]?(b[i]<<32)/a[i]:0;
}
sortA(n,c,a,b);
ll s=sum(a(n));
rep(i,n){
	s-=a[i]*2;
	if(s<0){
		wt(Mint(b[i])/a[i]);
		exit(0);
	}
}