#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <cmath>

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define PB push_back
#define ALL(a) (a).begin(),(a).end()
#define PII pair<int,int>
#define VS vector<string>
#define VD vector<double>
#define VL vector<long>
#define V(type) vector<type>
#define DEBUG(x) cout<<#x<<": "<<x<<endl

using namespace std;


VD Eratosthenes(int n, double p, double& result_p){
    VD koho, dst;
    
    FOR(i, 2, n+1){
        koho.push_back(i);
    }
    VD backup_koho = koho;
    //    if ( p != 1.0 ){
    REP(i, koho.size()){
        dst.push_back(koho[i]);
        
        int j = 0;
        //        if ( koho[i] > 1 ){
        double piv = backup_koho[i];
        while ( i + j * piv <= koho.size() - 1 ) {
            if ( koho[i + j * piv] >= 1 ) {
                koho[i + j * piv] = 1 - p;
                ++j;
                continue;
            }
            koho[i + j * piv] *= ( 1 - p );
            ++j;
        }
    }
    return dst;
}

int main(int argc, const char * argv[]) {
    
    int N;
    double P;
    VD result;
    double result_p = 0;
    cin >> N >> P;
    result = Eratosthenes(N, P, result_p);
    
    
    double sum = 0;
    FOR(i, 0, result.size()){
        if ( result[i] >= 1 ){
            sum++;
        } else {
            sum += result[i];
        }
        
    }
    
    printf("%f\n", sum);
    
    return 0;
}