using System;
public class halton{

int[] bs = new int[]
{2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67};
int n = 0,s=0,d=1;

public halton(int dim=1,int shift=0){
	d=dim;s=shift;
	if(d>bs.Length)throw new Exception($"halton d>{bs.Length}");
	if(d+s>bs.Length)throw new Exception($"halton d+s>{bs.Length}");
}

public static double corput(int n, int b){
	double q=0,bk=1.0/b;
	while(n>0){q+=(n%b)*bk;n/=b;bk/=b;}
	return q;
}

public vector next(){
	n++;
       	vector x=new vector(d);
       	for(int i=0;i<d;i++)x[i]=corput(n,bs[i+s]);
       	return x;
}

}//class