Problem:
Score : 100 points

Problem Statement

Snuke is giving cookies to his three goats.

He has two cookie tins. One contains A cookies, and the other contains B cookies. He can thus give A cookies, B cookies or A+B cookies to his goats (he cannot open the tins).

Your task is to determine whether Snuke can give cookies to his three goats so that each of them can have the same number of cookies.

Constraints

1 \leq A,B \leq 100

Both A and B are integers.

Input

Input is given from Standard Input in the following format:

A B

Output

If it is possible to give cookies so that each of the three goats can have the same number of cookies, print Possible; otherwise, print Impossible.

Sample Input 1

4 5

Sample Output 1

Possible

If Snuke gives nine cookies, each of the three goats can have three cookies.

Sample Input 2

1 1

Sample Output 2

Impossible

Since there are only two cookies, the three goats cannot have the same number of cookies no matter what Snuke gives to them.

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Text;
using System.Text.RegularExpressions;
using System.Diagnostics;
using System.Linq;
using System.Collections.Generic;
using System.IO;
using System.Numerics;

namespace competitive
{
    class Program
    {
        static void Main(string[] args)
        {
            var scanner = new Scanner();
            var a = scanner.NextInt();
            var b = scanner.NextInt();
            if (a % 3 == 0 || b % 3 == 0 || (a + b) % 3 == 0)
            {
                Console.WriteLine("Possible");
            }
            else
            {
                Console.WriteLine("Impossible");
            }
        }
    }

    public static class Extensions
    {
        public static int ToInt(this string str) => int.Parse(str);
        public static double ToDouble(this string str) => double.Parse(str);
        public static long ToLong(this string str) => long.Parse(str);
        public static BigInteger ToBigInteger(this string str) => BigInteger.Parse(str);
    }

    public class Scanner
    {
        private TextReader reader;
        public Scanner()
        {
            reader = Console.In;
        }
        public Scanner(TextReader reader)
        {
            this.reader = reader;
        }
        private string NextWord()
        {
            var sb = new StringBuilder();
            while (true)
            {
                var c = reader.Read();
                if (c == -1 || c == 13 || c == 10 || c == 32)
                {
                    break;
                }
                sb.Append((char)c);
            }
            return sb.ToString();
        }
        public int NextInt()
        {
            return NextWord().ToInt();
        }
        public string Next()
        {
            return NextWord();
        }
        public double NextDouble()
        {
            return NextWord().ToDouble();
        }
        public long NextLong()
        {
            return NextWord().ToLong();
        }
        public BigInteger NextBigInteger()
        {
            return NextWord().ToBigInteger();
        }
        public string NextLine()
        {
            return reader.ReadLine();
        }
    }
}