#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,a) for(int i=0;i<(a);i++)
#define MOD 1000000007

const int INF=INT_MAX/2;

int solve(int X,int Y){
  int res=0;
  while(X>Y){
    int tmp=X+Y;
    Y=X-Y;
    X=tmp;
    res++;
  }
  if(X==Y) return res;
  swap(X,Y);
  res++;
  while(X>Y){
    int tmp=X+Y;
    Y=X-Y;
    X=tmp;
    res++;
  }
  if(X==Y) return res;
  else return INF;
}

int main(){
  int X,Y; cin>>X>>Y;
  if(X==Y){
    cout<<0<<endl;
    return 0;
  }else if(X==0){
    cout<<2<<endl;
    return 0;
  }else if(Y==0){
    cout<<1<<endl;
    return 0;
  }else if(abs(X)==abs(Y)){
    cout<<3<<endl;
    return 0;
  }
  int ans=INF;
  ans=min(ans,solve(X,Y));
  ans=min(ans,solve(Y,X)+1);
  if(ans==INF) cout<<-1<<endl;
  else cout<<ans<<endl;
  return 0;
}