#include <iostream>
#include <iomanip>
using namespace std;
long double rr[1000001];

int main() {
	int n;
	long double k;
	cin>>n>>k;
	k=1.0-k;
	for(int i=2;i<=n;i++){
		rr[i]=1.0;
	}
	for(int i=2;i<=n/2+3;i++){
		long double k2=k;
		int p=i*2;
		while(p<=n){
			rr[p]=rr[p]*k2;
			p+=i;
		}
	}
	long double ans=0.0;
	for(int i=2;i<=n;i++){
		ans+=rr[i];
	}
	cout << fixed <<setprecision(8) << ans<<endl;
	return 0;
}