#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;




int main() {
	
	double a,b,c;
	cin>>a>>b;
	cout << setprecision(30);
	if(a==b){
		cout<<sqrt(a*a+b*b)<<endl;
		return 0;
	}
	if(a>b)swap(a,b);
	cout<<sqrt(b*b-a*a)<<endl;

	return 0;
}