#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
#include<Windows.h>
#include<stdio.h>

void main()
{
	float pn(float,int);
	float x, lyd;
	int n;
	scanf("%f%d", &x, &n);
	lyd = pn(x,n);
	printf("pn=%f", lyd);
	system("pause");
}
float pn(float x, int n)
{
	float temp;
	if (n == 0) temp = 1.0;
	else if (n == 1) temp = x;
	else temp=(((2*n - 1)*x*pn(x, n - 1) - (n - 1)*pn(x, n - 2)) / n);
	return(temp);
}