#include <bits/stdc++.h>
using namespace std;
using ld = long double;

int main(void) {
    ld a, b; cin >> a >> b; if (a < b) swap(a, b);
    cout << fixed << setprecision(40) << sqrtl(a * a + (a == b ? 1.0l : -1.0l) * b * b) << endl;
    return 0;
}