#include<iostream>
#include<algorithm>
#include<string>
#include<cmath>
#include<iomanip>
using namespace std;
//typedef __int64 LL;
int main(){
    long double a,b;
    cin>>a>>b;
    if(a>b)cout<<fixed<<setprecision(15)<<sqrt(a*a-b*b)<<endl;
    if(a<b)cout<<fixed<<setprecision(15)<<sqrt(-a*a+b*b)<<endl;
    if(a==b)cout<<fixed<<setprecision(15)<<sqrt(a*a+b*b)<<endl;
    return 0;
}