#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

signed main(){
    ios::sync_with_stdio(false);
	cin.tie(0);
 
    ll x,y;
    cin>>x>>y;
    int ans=0;
    if(x==y){
        cout<<0<<endl;
        return 0;
    }
    if(x==0){
        cout<<2<<endl;
        return 0;
    }
    if(y==0){
        cout<<1<<endl;
        return 0;
    }
    if(abs(x) == abs(y)){
        cout<<3<<endl;
        return 0;
    }
    cout<<-1<<endl;

}