#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll mod=998244353;
ll inf=1009999999999999990;
int main(){
    ld a,b;
    cin >> a >> b;
    if (a>b)
    {
        swap(a,b);
    }
    if (a==b)
    {
        cout << setprecision(100) << sqrt(b*b+a*a) << endl;
    }else{
        cout << setprecision(100) << sqrt(b*b-a*a) << endl;
    }
}