#include <stdio.h>
#include <stdlib.h>

int main(void) {
	int n, x, i;
	double p, mean = 0;
	double *list_of_koho;
	double *list_of_sosu;

	scanf("%d %lf", &n, &p);
	list_of_koho = (double *)malloc( sizeof( double ) * (n+1) );
	list_of_sosu = (double *)malloc( sizeof( double ) * (n+1) );
	for (i = 2; i <= n; i++) {
		list_of_koho[i] = 1;
		list_of_sosu[i] = 0;
	}
	for (x = 2; x <= n; x++) {
		list_of_sosu[x] = list_of_koho[x];
		list_of_koho[x] = 0;
		for (i = 2; x*i <= n; i++)
			list_of_koho[x*i] -= list_of_koho[x*i] * p;
	}
	for (i = 2; i <= n; i++) {
		mean += list_of_sosu[i];
	}
	printf("%.10f\n", mean);

	return 0;
}