#include <bits/stdc++.h>
using namespace std;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
using Int = long long;
const char newl = '\n';


template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  Int d1,d2;
  cin>>d1>>d2;
  if(d1*2==d2) drop(4);
  if(d1*2<d2) drop(0);
  if(d1==d2) drop(4);
  if(d1>d2) drop(0);
  assert(0);
  return 0;
}