#include "bits/stdc++.h" using namespace std; #define DEBUG(x) cout<<#x<<": "<<x<<endl; #define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl typedef long long ll; #define vi vector<int> #define vl vector<ll> #define vii vector< vector<int> > #define vll vector< vector<ll> > #define vs vector<string> #define pii pair<int,int> #define pis pair<int,string> #define psi pair<string,int> #define pll pair<ll,ll> const int inf = 1000000001; const ll INF = 2e18 * 2; #define MOD 1000000007 #define mod 1000000009 #define pi 3.14159265358979323846 #define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl; int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 }; int main() { int x, y; cin >> x >> y; if (x == y) { cout << 0 << endl; return 0; } if (x != 0 && y != 0 && x + y != 0) { cout << -1 << endl; return 0; } else if (x + y == 0) { cout << 3 << endl; return 0; } else { if (x == 0) { cout << 2 << endl; } else { cout << 1 << endl; } } }