#include<iostream>
#include<algorithm>
#include <iomanip>

using namespace std;

void aiko(double tp,double p);
double ans = 1.0 / 3.0;
double q;

int main(){
	int tp,tq;
	cin >> tp >> tq;
	double p;
	
	p = tp / 100.0;
	q = tq / 100.0;
	
	double paiko = 1.0 / 3.0;
	aiko(paiko,p);
	
	cout << fixed << setprecision(7) << ans << endl;
	return 0;
}

void aiko(double tp,double p){
	double duse = 1.0 - p;
	double kati = tp * duse * (1.0 / 3.0);
	double ai = kati;
	ans += kati;
	if(kati > (1.0 / 1e9)) aiko(ai,min(p+q,1.0));
	
	double ukati = tp * p * (1.0 / 2.0);
	double uai = ukati;
	ans += ukati;
	if(ukati > (1.0 / 1e9)) aiko(uai,max(p-q,0.0));
}