using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AtCoder
{
    partial class Program
    {
        static long mod = 1000000007;
        static void Main()
        {
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
            Solve();
            Console.Out.Flush();
            Console.ReadKey();
        }

        //ここから
        static void Solve()
        {
            long H;long W;
            Multi(out H, out W);
            if(H%3==0 || W % 3 == 0)
            {
                Console.WriteLine(0);
                return;
            }
            var min = long.MaxValue;
            var h = H / 3;
            var hh = H / 3 + 1;
            var w = W / 3;
            var ww = W / 3 + 1;

            var list = new List<long>();
            list.Add(h * W);
            var B = Math.Max((H - h), W);
            var S = Math.Min((H - h), W);
            if (B % 2 == 0 || S % 2 == 0)
            {
                list.Add(B * S / 2);
            }
            else
            {
                list.Add(B / 2 * S);
                list.Add(((B - (B / 2)) * S));
            }
            list = list.OrderBy(o => o).ToList();
            min = Math.Min(min, list.Last() - list.First());

            list = new List<long>();
            list.Add(hh * W);
            B = Math.Max((H - hh), W);
            S = Math.Min((H - hh), W);
            if (B % 2 == 0 || S % 2 == 0)
            {
                list.Add(B * S / 2);
            }
            else
            {
                list.Add(B / 2 * S);
                list.Add(((B - (B / 2)) * S));
            }
            list = list.OrderBy(o => o).ToList();
            min = Math.Min(min, list.Last() - list.First());

            list = new List<long>();
            list.Add(w * H);
            B = Math.Max((W-w), H);
            S = Math.Min((W-w), H);
            if (B % 2 == 0 || S % 2 == 0)
            {
                list.Add(B * S / 2);
            }
            else
            {
                list.Add(B / 2 * S);
                list.Add(((B - (B / 2)) * S));
            }
            list = list.OrderBy(o => o).ToList();
            min = Math.Min(min, list.Last() - list.First());

            list = new List<long>();
            list.Add(ww * H);
            B = Math.Max((W - ww), H);
            S = Math.Min((W - ww), H);
            if (B % 2 == 0 || S % 2 == 0)
            {
                list.Add(B * S / 2);
            }
            else
            {
                list.Add(B / 2 * S);
                list.Add(((B - (B / 2)) * S));
            }
            list = list.OrderBy(o => o).ToList();
            min = Math.Min(min, list.Last() - list.First());


            Console.WriteLine(min);
        }

    }



    //拡張メソッド
    public static class Ex
    {
        public static List<string> FastSort(this List<string> s) { s.Sort(StringComparer.Ordinal); return s.ToList(); }
        public static string yesno(this bool b) { return b ? "yes" : "no"; }
        public static string YesNo(this bool b) { return b ? "Yes" : "No"; }
        public static string YESNO(this bool b) { return b ? "YES" : "NO"; }
    }

    partial class Program
    {
        static public string GetStr() { return Console.ReadLine().Trim(); }
        static public char GetChar() { return Console.ReadLine().Trim()[0]; }
        static public int GetInt() { return int.Parse(Console.ReadLine().Trim()); }
        static public long GetLong() { return long.Parse(Console.ReadLine().Trim()); }
        static public double GetDouble() { return double.Parse(Console.ReadLine().Trim()); }
        static public string[] GetStrArray() { return Console.ReadLine().Trim().Split(' '); }
        static public int[] GetIntArray() { return Console.ReadLine().Trim().Split(' ').Select(int.Parse).ToArray(); }
        static public long[] GetLongArray() { return Console.ReadLine().Trim().Split(' ').Select(long.Parse).ToArray(); }
        static public char[] GetCharArray() { return Console.ReadLine().Trim().Split(' ').Select(char.Parse).ToArray(); }
        static public double[] GetDoubleArray() { return Console.ReadLine().Trim().Split(' ').Select(double.Parse).ToArray(); }
        static public T[][] CreateJaggedArray<T>(int H, int W, T value) { return Enumerable.Repeat(0, H).Select(s => Enumerable.Repeat(value, W).ToArray()).ToArray(); }
        static public int[][] GetIntJaggedArray(int N) { return Enumerable.Repeat(0, N).Select(s => GetIntArray().ToArray()).ToArray(); }
        static public long[][] GetLongJaggedArray(int N) { return Enumerable.Repeat(0, N).Select(s => GetLongArray().ToArray()).ToArray(); }
        static public char[][] GetCharJaggedArray(int N) { return Enumerable.Repeat(0, N).Select(s => GetStr().ToCharArray()).ToArray(); }
        static public double[][] GetDoubleJaggedArray(int N) { return Enumerable.Repeat(0, N).Select(s => GetDoubleArray()).ToArray(); }

        static public void WriteObjects<T>(IReadOnlyCollection<T> values) { var array = values.ToArray(); var num = array.Length; Console.Write(array[0]); for (int i = 1; i < num; i++) { Console.Write(" "+array[i]);} Console.WriteLine(); }

        static bool eq<T, U>() => typeof(T).Equals(typeof(U));
        static T ct<T, U>(U a) => (T)Convert.ChangeType(a, typeof(T));
        static T cv<T>(string s) => eq<T, int>() ? ct<T, int>(int.Parse(s))
                           : eq<T, long>() ? ct<T, long>(long.Parse(s))
                           : eq<T, double>() ? ct<T, double>(double.Parse(s))
                           : eq<T, char>() ? ct<T, char>(s[0])
                                             : ct<T, string>(s);
        static void Multi<T>(out T a) => a = cv<T>(GetStr());
        static void Multi<T, U>(out T a, out U b)
        {
            var ar = GetStrArray(); a = cv<T>(ar[0]); b = cv<U>(ar[1]);
        }
        static void Multi<T, U, V>(out T a, out U b, out V c)
        {
            var ar = GetStrArray(); a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]);
        }
        static void Multi<T, U, V, W>(out T a, out U b, out V c, out W d)
        {
            var ar = GetStrArray(); a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]);
        }
        static void Multi<T, U, V, W, X>(out T a, out U b, out V c, out W d, out X e)
        {
            var ar = GetStrArray(); a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]); e = cv<X>(ar[4]);
        }
        static void Multi<T, U, V, W, X,Y>(out T a, out U b, out V c, out W d, out X e,out Y f)
        {
            var ar = GetStrArray(); a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]); e = cv<X>(ar[4]);f = cv<Y>(ar[5]);
        }
    }
}


Measured memory_bytes: 11476