package main

import (
	"bufio"
	"os"
	"strconv"
	"fmt"
)

type Scanner struct {
	r   *bufio.Reader
	buf []byte
	p   int
}

func NewScanner() *Scanner {
	rdr := bufio.NewReaderSize(os.Stdin, 1000)
	return &Scanner{r:rdr}
}
func (s *Scanner) Next() string {
	s.pre()
	start := s.p
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			break
		}
	}
	result := string(s.buf[start:s.p])
	s.p++
	return result
}
func (s *Scanner) NextLine() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)
	return string(s.buf[start:])
}
func (s *Scanner) NextInt() int {
	v, _ := strconv.Atoi(s.Next())
	return v
}

func (s *Scanner) NextIntArray() []int {
	s.pre()
	start := s.p
	result := []int{}
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			v, _ := strconv.Atoi(string(s.buf[start:s.p]))
			result = append(result, v)
			start = s.p + 1
		}
	}
	v, _ := strconv.Atoi(string(s.buf[start:s.p]))
	result = append(result, v)

	return result
}

func (s *Scanner) NextMap() map[int]bool {
	s.pre()
	start := s.p
	mp := map[int]bool{}
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			v, _ := strconv.Atoi(string(s.buf[start:s.p]))
			mp[v] = true
			start = s.p + 1
		}
	}
	v, _ := strconv.Atoi(string(s.buf[start:s.p]))
	mp[v] = true

	return mp
}

func (s *Scanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}
func (s *Scanner) readLine() {
	s.buf = make([]byte, 0)
	for {
		l, p, e := s.r.ReadLine()
		if e != nil {
			panic(e)
		}
		s.buf = append(s.buf, l...)
		if !p {
			break
		}
	}
}

type Pos struct {
	x int
	y int
}

func main() {
	sc := NewScanner()
	h := sc.NextInt()
	w := sc.NextInt()
	s := [2]int{}
	g := [2]int{}

	s[0] = sc.NextInt() - 1
	s[1] = sc.NextInt() - 1
	g[0] = sc.NextInt() - 1
	g[1] = sc.NextInt() - 1

	field := make([][]int, h)
	checked := make([][]bool, h)

	for i := 0; i < h; i++ {
		field[i] = make([]int, w)
		checked[i] = make([]bool, w)

		l := sc.NextLine()
		for j := 0; j < w; j++ {
			field[i][j] = int(l[j] - '0')
		}
	}

	queue := []Pos{}
	queue = append(queue, Pos{x:s[1], y:s[0]})
	checked[s[0]][s[1]] = true
	vecp := []int{-1, 0, 1, 0}
	for p := 0; p < len(queue); p++ {
		cur := queue[p]
		if cur.y == g[0] && cur.x == g[1] {
			fmt.Println("YES")
			return
		}

		for i := 0; i < 8; i++ {
			a := vecp[i % 4]
			b := vecp[(i + 1) % 4]

			if i / 4 == 1 {
				a *= 2
				b *= 2
			}

			nx := cur.x + a
			ny := cur.y + b
			if checkRange(nx, 0, w) &&
				checkRange(ny, 0, h) {
				if checked[ny][nx] {
					continue
				}

				if i < 4 {
					if abs(field[ny][nx] - field[cur.y][cur.x]) <= 1 {
						queue = append(queue, Pos{x:nx, y:ny})
						checked[ny][nx] = true
					}
				} else {
					if field[ny][nx] == field[cur.y][cur.x] {
						if field[(ny + cur.y) / 2][(nx + cur.x) / 2] < field[ny][nx] {
							queue = append(queue, Pos{x:nx, y:ny})
							checked[ny][nx] = true

						}
					}
				}
			}
		}
	}
	fmt.Println("NO")
}
/**
 * [mn,mx) のチェックをします
 */
func checkRange(v, mn, mx int) bool {
	return mn <= v && v < mx

}
func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}