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

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    double A, B;
    cin >> A >> B;

    if(A>B){
        swap(A, B);
    }

    double C2;
    if(A==B){
        C2 = A*A + B*B;
    }else{
        C2 = B*B - A*A;
    }

    cout << setprecision(20);
    double ans = sqrt(C2);
    p(ans);
    
    return 0;
}