#include <iostream>
#include <algorithm>
using namespace std;
double p0,q;
const double eps = 10e-16;

double rec(double p, double c, bool b){
    if(c<eps) return 0;
    double ret=0;
    if(b){
        ret+=c/2;
        p=max(p-q,0.0);
        ret+=rec(p,c/2*p,true)+rec(p,c/2*(1-p),false);
        return ret;
    }else{
        ret+=c/3;
        p=min(p+q,1.0);
        ret+=rec(p,c/3*p,true)+rec(p,c/3*(1-p),false);
        return ret;
    }
}

int main(){
    cin>>p0>>q;
    p0/=100;q/=100;
    cout<<fixed;
    cout.precision(12);
    cout<<1/3.0+rec(p0,1/3.0*p0,true)+rec(p0,1/3.0*(1-p0),false)<<endl;
    return 0;
}