#include<iostream>
#include<cmath>
#include<iomanip>
#include<cassert>
using namespace std;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int a,b;cin>>a>>b;
	cout<<fixed<<setprecision(16)<<(a==b?a*sqrt(2):sqrt(max(a,b)*max(a,b)-min(a,b)*min(a,b)))<<endl;
}