#include <iostream>
#include <vector>
#include <algorithm>
#include <stdio.h>
#include <iomanip>
#include <map>
#include <set>
#include <math.h>

using namespace std;

#define rep(i,n) for(int i = 0; i < (n); i++)

typedef long long ll;
typedef long double lld;

const int MOD = 1000000007;
const lld PI = 3.14159265358979;

int main () {
    cout << fixed << setprecision(15);
    double a , b;
    cin >> a >> b;
    if (a < b)swap(a , b);
    double ans = a * a - b * b;
    cout << sqrt(ans) << endl;
    return 0;
}