#include <bits/stdc++.h>
using namespace std;

int main() {
	long n,i,j,k,cur,ans,p,q;
	cin >> p >> q;
	
	double l=1,r=1e12,m=0.5e12,f;
	while(abs(r-l)/m>0.000005 && abs(r-l)>0.000005){
		m=(l+r)/2;
		f=p+q*m*log(m)/log(2.0)-m*m;
		//cout << m << ' ' << f << endl;
		if(f>0){
			l=m;
		}else{
			r=m;
		}
	}
	cout << setprecision(12);
	cout << m << endl;
	return 0;
}