#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<stdlib.h>
#include<vector>
#include<string>
#include<sstream>
#include<math.h>
using namespace std;


int main(){

  int x, y;
  cin >> x >> y;

  double ans = 0;
  while( ans <= sqrt( x*x + y*y ) ){
    ans+=0.5;
  }
  cout << 2*ans << endl;


  return 0;
}