#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cmath>
#include <stack>
#include <cctype>
#include <stdio.h>
#include <map>
#include <string.h>

using namespace std;


int main() {

	double a=0.0,b=0.0;

	cin>>a>>b;

	if(a<b){
		swap(a,b);
	}

	if(a==b){
		cout<<setprecision(10)<<sqrt((a*a)+(b*b))<<endl;
		return 0;
	}

	cout<<setprecision(10)<<sqrt((a*a)-(b*b))<<endl;

	return 0;
}