#include <bits/stdc++.h>
using namespace std;

#define FOR(i,l,r) for(int i = (l);i < (r);i++)
#define PB push_back
#define MP make_pair
#define ALL(x) (x).begin(),(x).end()
typedef long long ll;

double A,B;

int main()
{
	cin >> A >> B;

	cout << fixed << setprecision(10);
	if(A > B){
		cout << sqrt(A * A - B * B) << endl;
	}
	else if(A == B){
		cout << sqrt(A * A + B * B) << endl;
	}
	else{
		cout << sqrt(B * B - A * A) << endl;
	}

	return 0;
}