h, w = gets.chomp.split(" ").map(&:to_i)
sy, sx, gy, gx = gets.chomp.split(" ").map(&:to_i)
one = [[0,1],[0,-1],[1,0],[-1,0],[0,2],[2,0],[-2,0],[0,-2]]
maze = []
h.times do |i|
    b = gets.chomp.split("").map(&:to_i)
    maze << b
end
st = [[sy-1,sx-1]]
arr = Array.new(h).map{Array.new(w,-1)}
arr[sy-1][sx-1] = 0
ok = false
until st == []
    i,j = st.pop
    one.each do |y,x|
        yy = i + y
        xx = j + x
        next if (i+y < 0 || i+y > h-1) || (j+x < 0 || j+x > w-1)
        next if arr[yy][xx] != -1
        if y.abs == 2 || x.abs == 2
            if maze[yy][xx] == maze[i][j]
                if y.abs == 2
                    yyy = i + (y/2)
                    if maze[yy][xx] > maze[yyy][xx]
                        arr[yy][xx] += 1
                        st << [yy,xx]
                    end
                else
                    xxx = j + (x/2)
                    if maze[yy][xx] > maze[yy][xxx]
                        arr[yy][xx] += 1
                        st << [yy,xx]
                    end
                end
            end
        else
            if (maze[yy][xx] - maze[i][j]).abs <= 1
                arr[yy][xx] += 1
                st << [yy,xx]
            end
        end
    end
    if arr[gy-1][gx-1] == 0
        ok = true
        break
    end
    # p st
end
if ok
    puts "YES"
else
    puts "NO"
end