using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace AtCorder
{
	public class Program
	{
		static void Main(string[] args)
		{
			var cin = new Scanner2();
			int h = cin.Int();
			int w = cin.Int();
			if (h % 3 == 0 || w % 3 == 0) {
				Console.WriteLine(0);
				return;
			}

			int ans = int.MaxValue;
			{
				int w2 = (w + 2) / 3;
				int h2 = h / 2;
				{
					int r1 = h * w2;
					int r2 = h2 * (w - w2);
					int r3 = (h - h2) * (w - w2);
					int max = Math.Max(r1, Math.Max(r2, r3));
					int min = Math.Min(r1, Math.Min(r2, r3));
					ans = Math.Min(ans, max - min);
				}

				if (w2 > 1) {
					w2 -= 1;
					int r1 = h * w2;
					int r2 = h2 * (w - w2);
					int r3 = (h - h2) * (w - w2);
					int max = Math.Max(r1, Math.Max(r2, r3));
					int min = Math.Min(r1, Math.Min(r2, r3));
					ans = Math.Min(ans, max - min);
				}

				if (w > 3) {
					ans = Math.Min(ans, h);
				}
			}

			{
				int h2 = (h + 2) / 3;
				int w2 = w / 2;
				{
					int r1 = w * h2;
					int r2 = w2 * (h - h2);
					int r3 = (w - w2) * (h - h2);
					int max = Math.Max(r1, Math.Max(r2, r3));
					int min = Math.Min(r1, Math.Min(r2, r3));
					ans = Math.Min(ans, max - min);
				}

				if (h2 > 1) {
					h2 -= 1;
					int r1 = w * h2;
					int r2 = w2 * (h - h2);
					int r3 = (w - w2) * (h - h2);
					int max = Math.Max(r1, Math.Max(r2, r3));
					int min = Math.Min(r1, Math.Min(r2, r3));
					ans = Math.Min(ans, max - min);
				}

				if (h > 3) {
					ans = Math.Min(ans, w);
				}
			}

			Console.WriteLine(ans);
		}
	}


	public class Scanner2
	{
		private readonly char[] delimiter_ = new char[] { ' ' };
		private readonly string filePath_;
		private readonly Func<string> reader_;
		private string[] buf_;
		private int index_;

		public Scanner2(string file = "")
		{
			if (string.IsNullOrWhiteSpace(file)) {
				reader_ = Console.ReadLine;
			} else {
				filePath_ = file;
				var fs = new StreamReader(file);
				reader_ = fs.ReadLine;
			}
			buf_ = new string[0];
			index_ = 0;
		}

		public string Next()
		{
			if (index_ < buf_.Length) {
				return buf_[index_++];
			}

			string st = reader_();
			while (st == "") {
				st = reader_();
			}

			buf_ = st.Split(delimiter_, StringSplitOptions.RemoveEmptyEntries);
			if (buf_.Length == 0) {
				return Next();
			}

			index_ = 0;
			return buf_[index_++];
		}

		public int Int() => int.Parse(Next());
		public long Long() => long.Parse(Next());
		public double Double() => double.Parse(Next());

		public int[] ArrayInt(int N, int add = 0)
		{
			int[] Array = new int[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Int() + add;
			}
			return Array;
		}

		public long[] ArrayLong(int N, long add = 0)
		{
			long[] Array = new long[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Long() + add;
			}
			return Array;
		}

		public double[] ArrayDouble(int N, double add = 0)
		{
			double[] Array = new double[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Double() + add;
			}
			return Array;
		}

		public void Save(string text)
		{
			if (string.IsNullOrWhiteSpace(filePath_)) {
				return;
			}

			File.WriteAllText(filePath_ + "_output.txt", text);
		}
	}
}

Measured memory_bytes: 11220