using static System.Math;
using System;

public class Hello
{
    static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var h = line[0];
        var s = line[1];
        getAns(h, s);
    }
    static void getAns(string h, string s)
    {
        var hL = h.Length;
        var sL = s.Length;
        var hh = h[hL - 1] - '0';
        var ss = s[sL - 1] - '0';
        var w = Abs(hh - ss);
        Console.WriteLine(w % 2 == 0 ? "Possible" : "Impossible");
    }
}