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: Accepted)

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using static System.Math;
using System.Text;
using System.Threading;
using System.Globalization;
using System.Runtime.CompilerServices;
using Library;
using System.Collections;
using System.Numerics;

namespace Program
{
    public static class ABC147E
    {
        static public int numberOfRandomCases = 0;
        static public void MakeTestCase(List<string> _input, List<string> _output, ref Func<string[], bool> _outputChecker)
        {
        }
        static public void Solve()
        {
            var H = NN;
            var W = NN;
            var A = new long[H, W];
            var B = new long[H, W];
            for (var i = 0; i < H; i++)
            {
                for (var j = 0; j < W; j++)
                {
                    A[i, j] = NN;
                }
            }
            for (var i = 0; i < H; i++)
            {
                for (var j = 0; j < W; j++)
                {
                    B[i, j] = NN;
                }
            }
            var dp = new LIB_Bitset[H, W];
            for (var i = 0; i < H; i++)
            {
                for (var j = 0; j < W; j++)
                {
                    var moved = (int)Abs(A[i, j] - B[i, j]);
                    dp[i, j] = new LIB_Bitset(12801);
                    if (i == 0 && j == 0)
                    {
                        dp[i, j][6400 - moved] = true;
                        dp[i, j][6400 + moved] = true;
                    }
                    if (i != 0)
                    {
                        dp[i, j].Or(dp[i - 1, j] >> moved);
                        dp[i, j].Or(dp[i - 1, j] << moved);
                    }
                    if (j != 0)
                    {
                        dp[i, j].Or(dp[i, j - 1] >> moved);
                        dp[i, j].Or(dp[i, j - 1] << moved);
                    }
                }
            }
            var ans = 10000000000;
            for (var i = 0; i < 12801; i++)
            {
                if (dp[H - 1, W - 1][i])
                {
                    ans = Min(ans, Abs(6400 - i));
                }
            }
            Console.WriteLine(ans);
        }
        static class Console_
        {
            static Queue<string> param = new Queue<string>();
            public static string NextString() { if (param.Count == 0) foreach (var item in Console.ReadLine().Split(' ')) param.Enqueue(item); return param.Dequeue(); }
        }
        class Printer : StreamWriter
        {
            public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
            public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { base.AutoFlush = false; }
            public Printer(Stream stream, Encoding encoding) : base(stream, encoding) { base.AutoFlush = false; }
        }
        static public void Main(string[] args) { if (args.Length == 0) { Console.SetOut(new Printer(Console.OpenStandardOutput())); } var t = new Thread(Solve, 134217728); t.Start(); t.Join(); Console.Out.Flush(); }
        static long NN => long.Parse(Console_.NextString());
        static double ND => double.Parse(Console_.NextString());
        static string NS => Console_.NextString();
        static long[] NNList(long N) => Repeat(0, N).Select(_ => NN).ToArray();
        static double[] NDList(long N) => Repeat(0, N).Select(_ => ND).ToArray();
        static string[] NSList(long N) => Repeat(0, N).Select(_ => NS).ToArray();
        static IEnumerable<T> OrderByRand<T>(this IEnumerable<T> x) => x.OrderBy(_ => xorshift);
        static long Count<T>(this IEnumerable<T> x, Func<T, bool> pred) => Enumerable.Count(x, pred);
        static IEnumerable<T> Repeat<T>(T v, long n) => Enumerable.Repeat<T>(v, (int)n);
        static IEnumerable<int> Range(long s, long c) => Enumerable.Range((int)s, (int)c);
        static uint xorshift { get { _xsi.MoveNext(); return _xsi.Current; } }
        static IEnumerator<uint> _xsi = _xsc();
        static IEnumerator<uint> _xsc() { uint x = 123456789, y = 362436069, z = 521288629, w = (uint)(DateTime.Now.Ticks & 0xffffffff); while (true) { var t = x ^ (x << 11); x = y; y = z; z = w; w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)); yield return w; } }
    }
}
namespace Library {
    class LIB_BitUtil
    {
        public static readonly ulong[] BitMask;
        static LIB_BitUtil()
        {
            BitMask = new ulong[64];
            BitMask[0] = 1;
            for (var i = 1; i < 64; i++) BitMask[i] = BitMask[i - 1] << 1;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public IEnumerable<long> ScanOne(long value)
        {
            for (; value > 0; value &= value - 1) yield return value & -value;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public long CountOne(ulong value)
        {
            value = (value & 0x5555555555555555) + ((value >> 1) & 0x5555555555555555);
            value = (value & 0x3333333333333333) + ((value >> 2) & 0x3333333333333333);
            value = (value & 0x0f0f0f0f0f0f0f0f) + ((value >> 4) & 0x0f0f0f0f0f0f0f0f);
            value = (value & 0x00ff00ff00ff00ff) + ((value >> 8) & 0x00ff00ff00ff00ff);
            value = (value & 0x0000ffff0000ffff) + ((value >> 16) & 0x0000ffff0000ffff);
            value = (value & 0x00000000ffffffff) + ((value >> 32) & 0x00000000ffffffff);
            return (long)value;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public long CountOne(long value) => CountOne((ulong)value);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public bool IsSet(ulong value, int idx) => (value & BitMask[idx]) != 0;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public bool IsSet(long value, int idx) => IsSet((ulong)value, idx);
    }
    class LIB_Bitset : IEquatable<LIB_Bitset>
    {
        long n;
        ulong[] ary;
        static readonly ulong[] ceil;
        static LIB_Bitset()
        {
            ceil = new ulong[64];
            ceil[0] = 0xffffffffffffffff;
            ceil[1] = 1;
            for (var i = 2; i < 64; i++)
            {
                ceil[i] = (ceil[i - 1] << 1) | 1;
            }
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_Bitset(long size)
        {
            if (size <= 0) throw new Exception();
            n = size;
            ary = new ulong[((n - 1) >> 6) + 1];
        }
        public long Count => n;
        public long CountOne => ary.Sum(e => LIB_BitUtil.CountOne(e));
        public bool this[int idx]
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get { return LIB_BitUtil.IsSet(ary[idx >> 6], idx & 63); }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            set
            {
                if (value) ary[idx >> 6] |= LIB_BitUtil.BitMask[idx & 63];
                else ary[idx >> 6] &= ~LIB_BitUtil.BitMask[idx & 63];
            }
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void And(LIB_Bitset x)
        {
            for (var i = 0; i < ary.Length; i++) ary[i] &= x.ary[i];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public LIB_Bitset operator &(LIB_Bitset x, LIB_Bitset y)
        {
            var ret = new LIB_Bitset(x.n);
            for (var i = 0; i < ret.ary.Length; i++) ret.ary[i] = x.ary[i] & y.ary[i];
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Or(LIB_Bitset x)
        {
            for (var i = 0; i < ary.Length; i++) ary[i] |= x.ary[i];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public LIB_Bitset operator |(LIB_Bitset x, LIB_Bitset y)
        {
            var ret = new LIB_Bitset(x.n);
            for (var i = 0; i < ret.ary.Length; i++) ret.ary[i] = x.ary[i] | y.ary[i];
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Xor(LIB_Bitset x)
        {
            for (var i = 0; i < ary.Length; i++) ary[i] ^= x.ary[i];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public LIB_Bitset operator ^(LIB_Bitset x, LIB_Bitset y)
        {
            var ret = new LIB_Bitset(x.n);
            for (var i = 0; i < ret.ary.Length; i++) ret.ary[i] = x.ary[i] ^ y.ary[i];
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Flip()
        {
            for (var i = 0; i < ary.Length; i++) ary[i] = ~ary[i];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public LIB_Bitset operator ~(LIB_Bitset x)
        {
            var ret = new LIB_Bitset(x.n);
            for (var i = 0; i < ret.ary.Length; i++) ret.ary[i] = ~x.ary[i];
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ShiftLeft(int num)
        {
            var moveCnt = num >> 6;
            var moveBit = num & 63;
            for (var i = ary.Length - 1; i >= moveCnt; i--)
            {
                ary[i] = ary[i - moveCnt] << moveBit;
                if (moveBit > 0 && i > moveCnt) ary[i] |= ary[i - moveCnt - 1] >> (64 - moveBit);
            }
            ary[ary.Length - 1] &= ceil[n & 63];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public LIB_Bitset operator <<(LIB_Bitset x, int num)
        {
            var ret = new LIB_Bitset(x.n);
            var moveCnt = num >> 6;
            var moveBit = num & 63;
            for (var i = ret.ary.Length - 1; i >= moveCnt; i--)
            {
                ret.ary[i] = x.ary[i - moveCnt] << moveBit;
                if (moveBit > 0 && i > moveCnt) ret.ary[i] |= x.ary[i - moveCnt - 1] >> (64 - moveBit);
            }
            ret.ary[ret.ary.Length - 1] &= ceil[ret.n & 63];
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ShiftRight(int num)
        {
            var moveCnt = num >> 6;
            var moveBit = num & 63;
            var aryMax = ary.Length - moveCnt;
            for (var i = 0; i < aryMax; i++)
            {
                ary[i] = ary[i + moveCnt] >> moveBit;
                if (moveBit > 0 && i < aryMax - 1) ary[i] |= ary[i + moveCnt + 1] << (64 - moveBit);
            }
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public LIB_Bitset operator >>(LIB_Bitset x, int num)
        {
            var ret = new LIB_Bitset(x.n);
            var moveCnt = num >> 6;
            var moveBit = num & 63;
            var aryMax = ret.ary.Length - moveCnt;
            for (var i = 0; i < aryMax; i++)
            {
                ret.ary[i] = x.ary[i + moveCnt] >> moveBit;
                if (moveBit > 0 && i < aryMax - 1) ret.ary[i] |= x.ary[i + moveCnt + 1] << (64 - moveBit);
            }
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public bool operator ==(LIB_Bitset x, LIB_Bitset y) => x.n == y.n && Enumerable.Range(0, x.ary.Length).All(e => x.ary[e] == y.ary[e]);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        static public bool operator !=(LIB_Bitset x, LIB_Bitset y) => !(x == y);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public bool Equals(LIB_Bitset x) => x == this;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public override bool Equals(object x) => x == null ? false : Equals((LIB_Bitset)x);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public override int GetHashCode()
        {
            var t = ary.Aggregate((a, x) => a ^ x);
            return (int)(((t >> 32) ^ t) & 0x00000000ffffffff);
        }
    }
}