#include <cstdio>

bool isNotPrime[1000001];
int minFactor[1000001];

double pow(double a, int n){
    double res = 1.0f;
    while(n > 0){
        if(n & 1){res *= a;}
        a *= a;
        n >>= 1;
    }
    return res;
}

int main(){
    int N;
    double p;
    scanf("%d %lf", &N, &p);
    
    for(int i=4;i<=N;i+=2){
        isNotPrime[i] = true;
        minFactor[i] = 2;
    }
    minFactor[2] = 2;
    for(int i=3;i<=N;i+=2){
        if(!isNotPrime[i]){
            minFactor[i] = i;
            for(int j=2*i;j<=N;j+=i){
                isNotPrime[j] = true;
                minFactor[j] = i;                
            }
        }
    }

    double res = 0.0f;
    for(int i=2;i<=N;i++){
        if(!isNotPrime[i]){res += 1.0f; continue;}
        
        int x = i, count = 1;
        while(x > 1){
            int mF = minFactor[x], c = 0;
            while(x % mF == 0){c++; x /= mF;}
            count *= c + 1;
        }

        // printf("%d: %d\n", i, count-2);
        res += pow(1-p, count-2);
    }

    printf("%.10f\n", res);
    
}