#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; }