#include<bits/stdc++.h>

using namespace std;

int main(){
    double a,b,x,y;cin>>a>>b;
    tie(x,y)=minmax(a,b);
    cout<<fixed;
    cout<<setprecision(10);
    if(x==y)cout<<sqrt(x*x+y*y)<<endl;
    else cout<<sqrt(y*y-x*x)<<endl;

    return 0;
}