#include <iostream>
#include <iomanip>
#include <cmath>
int main()
{
    int x, y;std::cin >> x >> y;
    x = std::abs(x), y=std::abs(y);
    const int R = x*x+y*y;
    int min = 1<<30;
    for(int i =0; i <= 2*x+1; i++){
        for(int j =0; j <=2*y+1; j++){
            const int r = i*i+j*j;
            if(r>R){min = std::min(min, r);}
        }
    }
    std::cout << std::fixed << std::setprecision(15)<< std::sqrt((long double)(min)*2)<< std::endl;
    return 0;
}