#include <cmath>
#include <vector>
#include <map>
#include <functional>
#include <queue>
#include <iostream>
#include <string>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdint>
#include <climits>

using namespace std;

#define ll long long int
#define ti4 tuple<int,int,int,int>
#define pii pair<ll,ll>

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val){
    std::fill( (T*)array, (T*)(array+N), val );
}

ll comb(ll n, ll a)
{
    ll c = 1;
    for(ll i = 1;i < 1 + a;i++)
    {
        ll v = n - i + 1;
        c *= v;
        c /= i;
    }
    return c;
}

int main()
{
    ll a, b;
    cin >> a >> b;
    cout << std::fixed;
    cout << std::setprecision(10);
    if(a == b)
    {
        cout << sqrt(a * a + b * b) << endl;
        return 0;
    }
    ll u = max(a, b);
    ll l = min(a, b);
    cout << sqrt(u * u - l * l) << endl;
    return 0;
    
}