#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

int main()
{
    int a, b;
    cin >> a >> b;

    double ans;
    if(a == b){
        ans = sqrt(a * a + b * b);
    }
    else{
        if(a < b)
            swap(a, b);
        ans = sqrt(a * a - b * b);
    }
    printf("%.10f\n", ans);

    return 0;
}