#include<iostream>
#include<iomanip>
#include<cmath>

using namespace std;
using ld = long double;

int main(){
    cout << fixed << setprecision(15);
    ld a,b;
    cin >> a >> b;
    
    ld c1 = sqrtl(a*a+b*b);
    ld c2 = a > b ? sqrtl(a*a-b*b) : sqrtl(b*b-a*a);
    
    ld ans = c1 > c2 && c2 != 0 ? c2 : c1;
    cout << ans << endl;
    return 0;
}