#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define int long long
using namespace std;

signed main(){
    double a, b, c;
    cin >> a >> b;
    if(a < b) swap(a, b);
    c = sqrt(a * a - b * b);
    if((int)(a - b) == 0) c = sqrt(a * a + b * b);
    printf("%.10lf\n", c);
}