Problem:
Score : 500 points

Problem Statement

We have a grid with H horizontal rows and W vertical columns. Let (i,j) denote the square at the i-th row from the top and the j-th column from the left.

The square (i, j) has two numbers A_{ij} and B_{ij} written on it.

First, for each square, Takahashi paints one of the written numbers red and the other blue.

Then, he travels from the square (1, 1) to the square (H, W). In one move, he can move from a square (i, j) to the square (i+1, j) or the square (i, j+1). He must not leave the grid.

Let the unbalancedness be the absolute difference of the sum of red numbers and the sum of blue numbers written on the squares along Takahashi's path, including the squares (1, 1) and (H, W).

Takahashi wants to make the unbalancedness as small as possible by appropriately painting the grid and traveling on it.

Find the minimum unbalancedness possible.

Constraints

2 \leq H \leq 80

2 \leq W \leq 80

0 \leq A_{ij} \leq 80

0 \leq B_{ij} \leq 80

All values in input are integers.

Input

Input is given from Standard Input in the following format:

H W
A_{11} A_{12} \ldots A_{1W}
:
A_{H1} A_{H2} \ldots A_{HW}
B_{11} B_{12} \ldots B_{1W}
:
B_{H1} B_{H2} \ldots B_{HW}

Output

Print the minimum unbalancedness possible.

Sample Input 1

2 2
1 2
3 4
3 4
2 1

Sample Output 1

0

By painting the grid and traveling on it as shown in the figure below, the sum of red numbers and the sum of blue numbers are 3+3+1=7 and 1+2+4=7, respectively, for the unbalancedness of 0.

Sample Input 2

2 3
1 10 80
80 10 1
1 2 3
4 5 6

Sample Output 2

2

Solution in C# (Mono 4.6.2.0) (judge verdict: Time Limit Exceeded)

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

namespace ProgrammingContestTemplateByDotNetCore
{
    #region "Input and Output Classes"

    class Scanner : IDisposable
    {
        private readonly Queue<string> _buffer;
        private readonly char[] _sep;
        private readonly TextReader _reader;

        public Scanner(TextReader reader = null, char[] sep = null)
        {
            _buffer = new Queue<string>();
            _sep = sep ?? new[] { ' ' };
            _reader = reader ?? Console.In;
        }

        public Scanner(string path, char[] sep = null)
            : this(new StreamReader(path), sep) { }

        private void CheckBuffer()
        {
            if (_buffer.Any() || _reader.Peek() == -1)
                return;

            string str = string.Empty;
            for (;
                string.IsNullOrWhiteSpace(str);
                str = _reader.ReadLine()) { }

            var values = str.Split(_sep).Where(s => !string.IsNullOrWhiteSpace(s));
            foreach (var item in values)
            {
                _buffer.Enqueue(item);
            }
        }

        public string Next()
        {
            CheckBuffer();
            return _buffer.Dequeue();
        }
        public string[] GetStringArray(int count)
            => Enumerable.Range(0, count)
                .Select(e => Next())
                .ToArray();

        public int NextInt() => int.Parse(Next());
        public int[] GetIntArray(int count)
            => Enumerable.Range(0, count)
                .Select(e => NextInt())
                .ToArray();

        public long NextLong() => long.Parse(Next());
        public long[] GetLongArray(int count)
            => Enumerable.Range(0, count)
                .Select(e => NextLong())
                .ToArray();

        public double NextDouble() => double.Parse(Next());
        public double[] GetDoubleArray(int count)
            => Enumerable.Range(0, count)
                .Select(e => NextDouble())
                .ToArray();

        public decimal NextDecimal() => decimal.Parse(Next());
        public decimal[] GetDecimalArray(int count)
            => Enumerable.Range(0, count)
                .Select(e => NextDecimal())
                .ToArray();

        public BigInteger NextBigInt() => BigInteger.Parse(Next());
        public BigInteger[] GetBigIntArray(int count)
            => Enumerable.Range(0, count)
                .Select(e => NextBigInt())
                .ToArray();

        public bool IsEnd
        {
            get
            {
                CheckBuffer();
                return !_buffer.Any();
            }
        }

        public void Dispose()
        {
            if (!_reader.Equals(Console.In))
                _reader.Dispose();
        }
    }

    class Writer : IDisposable
    {
        private readonly TextWriter _writer;
        private readonly StringBuilder _cache;
        private readonly bool _isReactive;

        public Writer(TextWriter writer = null, bool isReactive = false)
        {
            _writer = writer ?? Console.Out;
            _isReactive = isReactive;
            if (!_isReactive)
                _cache = new StringBuilder();
        }

        public Writer(string path)
            : this(new StreamWriter(path)) { }

        public Writer(bool isReactive)
            : this(null, isReactive) { }

        public void Write(object value)
        {
            if (_isReactive)
            {
                _writer.Write(value);
                _writer.Flush();
            }
            else
            {
                _cache.Append(value);
            }
        }

        public void WriteFormat(string format, params object[] values)
        {
            var value = string.Format(format, values);
            Write(value);
        }

        public void WriteLine(object value = null)
        {
            Write($"{value}{Environment.NewLine}");
        }

        public void WriteLine(string format, params object[] values)
        {
            WriteFormat($"{format}{Environment.NewLine}", values);
        }

        public void Dispose()
        {
            if (!_isReactive)
            {
                _writer.Write(_cache);
                _writer.Flush();
            }
            if (!_writer.Equals(Console.Out))
            {
                _writer.Dispose();
            }
        }
    }

    public static class Extensions
    {
        public static void Set<TKey, TValue>(
            this IDictionary<TKey, TValue> source,
            TKey key, TValue value)
        {
            if (source.ContainsKey(key))
                source[key] = value;
            else
                source.Add(key, value);
        }

        public static void Update<TKey, TValue>(
            this IDictionary<TKey, TValue> source,
            TKey key, Func<TValue, TValue> update)
        {
            if (!source.ContainsKey(key))
                source.Add(key, default(TValue));
            source[key] = update(source[key]);
        }
    }

#endregion

    class MainClass : IDisposable
    {
#region "Template"

        /// <summary> 入力を受け取る </summary>
        private readonly Scanner sc;
        /// <summary> 出力を行う </summary>
        private readonly Writer wr;
        private const string _inputFile = "input.txt";
        private const string _outFile = "output.txt";

        static void Main(string[] args)
        {
            using (new MainClass()) { }
        }

        public MainClass()
        {
            wr = new Writer(_isReactive);
            // TODO: ファイルに出力したい場合はこっち → wr = new Writer(_outFile);

#if DEBUG
            // 手元では、ファイルから入力を受け取る
            sc = new Scanner(_inputFile);
#else

            // 提出時、標準入力から受け取る
            sc = new Scanner();
#endif

            Solve();
        }

        public void Dispose()
        {
            sc?.Dispose();
            wr?.Dispose();
        }

        #endregion

        void Solve()
        {
            int H = sc.NextInt();
            int W = sc.NextInt();
            var A = new int[H, W];
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    A[i, j] = sc.NextInt();
                }
            }
            var B = new int[H, W];
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    B[i, j] = sc.NextInt();
                }
            }

            const int Max = 81 * 81 * 2;
            bool[,,] dp = new bool[H, W, Max];
            dp[0, 0, Math.Abs(A[0, 0] - B[0, 0])] = true;
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    for (int k = 0; k < Max; k++)
                    {
                        if (!dp[i, j, k]) continue;

                        if (i + 1 < H)
                        {
                            dp[i + 1, j, Math.Abs(k + Math.Abs(A[i + 1, j] - B[i + 1, j]))] = true;
                            dp[i + 1, j, Math.Abs(k - Math.Abs(A[i + 1, j] - B[i + 1, j]))] = true;
                        }
                        if (j + 1 < W)
                        {
                            dp[i, j + 1, Math.Abs(k + Math.Abs(A[i, j + 1] - B[i, j + 1]))] = true;
                            dp[i, j + 1, Math.Abs(k - Math.Abs(A[i, j + 1] - B[i, j + 1]))] = true;
                        }
                    }
                }
            }

            var ans = Enumerable.Range(0, Max).First(i => dp[H - 1, W - 1, i]);
            wr.WriteLine(ans);
        }

        /// <summary>
        /// TODO: リアクティブ問題か否かを指定してね♪
        /// </summary>
        private const bool _isReactive = false;
    }
}