// yukicoder: No.144 エラトステネスのざる
// 2019.7.11 bal4u

#include <stdio.h>
#include <math.h>

#define EQ(a, b) (fabs((a)-(b)) < 1e-8)

double p;
int f[1000005];
double memo[300]; char sw[300];

int main()
{
	int i, j, n, N;
	double p, ans;
	
	scanf("%d%lf", &N, &p); n = N >> 1, p = 1-p;
	for (i = 2; i <= n; i++) for (j = i << 1; j <= N; j += i) f[j]++;
	
	if (EQ(p, 1)) ans = N-1;
	else if (EQ(p, 0)) while (N > 1) ans += (f[N--] == 0);
	else {
		ans = 0;
		while (N > 1) {
			n = f[N];
			if (!sw[n]) memo[n] = pow(p, n), sw[n] = 1;
			ans += memo[n];
			N--;
		}
	}
	printf("%.10lf\n", ans);
	return 0;
}