#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using Graph=vector<vector<pair<int,int>>>;
#define INF 1000000000000000000
#define MOD 1000000007

int main(){
  ll A,B;
  cin>>A>>B;
  if(B==0){
    cout<<1<<endl;
  }else if(A==-1){
    cout<<2<<endl;
  }else{
    cout<<-1<<endl;
  }
}