#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

int main() {
    double a, b;
    cin >> a >> b;
    if(b > a) {
        double temp = a;
        a = b;
        b = temp;
    }
    cout << fixed << setprecision(6) << sqrt(a*a - b*b) << endl;
}