#include <bits/stdc++.h>

using namespace std;

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int a,b;

    cin >> a >> b;

    int A = min(a,b);
    int B = max(a,b);

    double c = sqrt(B*B - A*A);
    double d = sqrt(B*B + A*A);

    cout << fixed;
    cout.precision(16);

    if(a==b)
    {
        cout << d << '\n';
    }
    else
    {
        cout << c << '\n';
    }

    return 0;
}