using System;
using System.Linq;

namespace No424_2{
    public class Program{
        public static void Main(string[] args){
            var sr = new StreamReader();
            //---------------------------------
            var H = sr.Next<int>();
            var W = sr.Next<int>();
            var Sy = sr.Next<int>() - 1;
            var Sx = sr.Next<int>() - 1;
            var Gy = sr.Next<int>() - 1;
            var Gx = sr.Next<int>() - 1;
            var B = sr.Next<string>(H).Select(s => s.Select(c => c - '0').ToArray()).ToArray();

            var dx = new[]{0, 1, 0, -1};
            var dy = new[]{1, 0, -1, 0};
            Func<int, int, bool> isInside = (x, y) => 0 <= x && x < W && 0 <= y && y < H;
            Func<int, int, int> hash = (x, y) => x + y * W;
            var uf = new UnionFind(H * W);

            for(var y = 0; y < H; y++){
                for(var x = 0; x < W; x++){
                    for(var i = 0; i < 4; i++){
                        var nx = x + dx[i];
                        var ny = y + dy[i];
                        var nnx = nx + dx[i];
                        var nny = ny + dy[i];
                        if(isInside(nx, ny) && Math.Abs(B[y][x] - B[ny][nx]) <= 1){
                            uf.Unite(hash(x, y), hash(nx, ny));
                        }
                        if(isInside(nnx, nny) && B[y][x] == B[nny][nnx] && B[ny][nx] < B[y][x]){
                            uf.Unite(hash(x, y), hash(nnx, nny));
                        }
                    }
                }
            }

            Console.WriteLine(uf.IsSameSet(hash(Sx, Sy), hash(Gx, Gy)) ? "YES" : "NO");
            //---------------------------------
        }
    }

    public class UnionFind{
        private readonly int[] _rank;
        private readonly int[] _p;

        public UnionFind(int size){
            _rank = new int[size];
            _p = new int[size];

            for(var i = 0; i < size; i++){
                _rank[i] = 0;
                _p[i] = i;
            }
        }

        public void Unite(int x, int y){
            x = FindSet(x);
            y = FindSet(y);

            if(_rank[x] > _rank[y]) _p[y] = x;
            if(_rank[x] < _rank[y]) _p[x] = y;
            if(_rank[x] == _rank[y]){
                _p[x] = y;
                _rank[y]++;
            }
        }

        public bool IsSameSet(int x, int y){
            return FindSet(x) == FindSet(y);
        }

        public int FindSet(int x){
            if(_p[x] == x) return x;
            return _p[x] = FindSet(_p[x]);
        }
    }

    public class StreamReader{
        private readonly char[] _c = {' '};
        private int _index = -1;
        private string[] _input = new string[0];
        private readonly System.IO.StreamReader _sr = new System.IO.StreamReader(Console.OpenStandardInput());

        public T Next<T>(){
            if(_index == _input.Length - 1){
                _index = -1;
                while(true){
                    string rl = _sr.ReadLine();
                    if(rl == null){
                        if(typeof(T).IsClass) return default(T);
                        return (T)typeof(T).GetField("MinValue").GetValue(null);
                    }
                    if(rl != ""){
                        _input = rl.Split(_c, StringSplitOptions.RemoveEmptyEntries);
                        break;
                    }
                }
            }
            return (T)Convert.ChangeType(_input[++_index], typeof(T), System.Globalization.CultureInfo.InvariantCulture);
        }

        public T[] Next<T>(int x){
            var ret = new T[x];
            for(var i = 0; i < x; ++i) ret[i] = Next<T>();
            return ret;
        }

        public T[][] Next<T>(int y, int x){
            var ret = new T[y][];
            for(var i = 0; i < y; ++i) ret[i] = Next<T>(x);
            return ret;
        }
    }
}