#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(10) << ans << endl;
	return 0;
}

void aiko(double tp,double p){
	ans += tp * (1.0 - p) * (1.0 / 3.0);
	if(tp * (1.0 - p) * (1.0 / 3.0) > (1.0 / 1e14)) aiko(tp * (1.0 - p) * (1.0 / 3.0),min(p+q,1.0));
	
	ans += tp * p * 0.5;
	if(tp * p * 0.5 > (1.0 / 1e14)) aiko(tp * p * 0.5,max(p-q,0.0));
}