#include <stdio.h>

int main(void) {
	int n, x, i;
	float p, mean = 0;
	float list_of_koho[n+1];
	float list_of_sosu[n+1];

	scanf("%d %f", &n, &p);
	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("%f\n", mean);

	return 0;
}