using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Globalization;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (a, b) = (c[0], c[1]);
        if (b == 0)
        {
            WriteLine(1);
        }
        else if (a >= 0)
        {
            WriteLine(-1);
        }
        else if (a == -1)
        {
            WriteLine(2);
        }
        else
        {
            WriteLine(-1);
        }
    }
}