#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
//#define int long long
using namespace std;

double a, b;

signed main()
{
	cin >> a >> b;
	printf("%.11lf", min(sqrt(a*a - b*b), min(sqrt(a*a + b*b), sqrt(b*b - a*a))));
}