#include <stdio.h>
#include <math.h>
void nhap (double &x, double &n);
double tinhLuyThua (double x, double n);
void xuat (double a);
void main ()
{
	double x,n;
	nhap (x,n);
	double a=tinhLuyThua (x,n);
	xuat (x);
}
void nhap (double &x, double &n)
{
	scanf ("%lf%lf",&x,&n);
}
double tinhLuyThua (double x, double n)
{
	double i=1;
	double s=0;
	while (i<=n)
	{
		s=s+pow (x,i);
		i++;
	}
	return s;
}
void xuat (double a)
{
	printf ("%lf",a);
}