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

int main() {
    int a, b;
    cin >> a >> b;

    int cc = max(a, b);
    int bb = min(a, b);
    if(cc > bb) {
        printf("%.8f\n", sqrt((double)cc*cc - bb*bb));
    } else {
        printf("%.8f\n", (double)cc * sqrt(2.0));
    }
}