#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<n; ++i)
#define repl(i,m,n) for(ll i=m; i<n; ++i)

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

    if(a == b){
        double ans = sqrt(2.0)*double(a);
        printf("%.10f\n", ans);
    }else{
        if(a < b) swap(a, b);
        double ans = 1e9;
        ans = min(ans, double(sqrt(double(a)*double(a) + double(b)*double(b))));
        ans = min(ans, double(sqrt(double(a)*double(a) - double(b)*double(b))));
        printf("%.10f\n", ans); 
    }  

    return 0;
}