# your code goes here
#rabirynce
def ab(a1):
    if a1<0:
        a1*=-1
    return a1
h,w=(int(i) for i in input().split())
sx,sy,gx,gy=(int(i) for i in input().split())
sx-=1
sy-=1
gx-=1
gy-=1
b=[list(input()) for i in range(h)]
for i in range(h):
    for j in range(w):
        b[i][j]=int(b[i][j])
vn=[[sx,sy]]
v=[[0,0]]
Nd=0
i=0
a=[]
for i in range(h):
    a.append([])
    for j in range(w):
        a[i].append(0)
a[sx][sy]=1
if sx==gx and sy==gy:
    Nd=1
while Nd<1 and vn!=[] and i<h*w+1:
    j=0
    v=vn
    vn=[]
    while j<len(v):
        tx=v[j][0]
        ty=v[j][1]
        k=-1
        while k<2:
          #  print(k)
  #          print("k")
            l=-1
            while l<2:
                if ab(k)+ab(l)<2:
         #           print(k)
            #        print(l)
                    ux=tx+k
                    uy=ty+l
                    if ux>=0 and ux<h and uy>=0 and uy<w and a[ux][uy]==0:
              #          print("u")
                        if b[tx][ty]==b[ux][uy] or ab(b[tx][ty]-b[ux][uy])==1:
                  #          print(b)
                            if ux==gx and uy==gy:
                                Nd=1
                            a[ux][uy]=1
                            vn.append([ux,uy])
                      #      print(vn)
                        elif b[tx][ty]>b[ux][uy]:
                            u1x=ux+k
                            u1y=uy+l
                #            print(u1x)
                            if u1x>=0 and u1x<h and u1y>=0 and u1y<w and a[u1x][u1y]==0:
                                if b[tx][ty]==b[u1x][u1y]:
                                    if u1x==gx and u1y==gy:
                                        Nd=1
                                    a[u1x][u1y]=1
                                    vn.append([u1x,u1y])
                l+=1
            k+=1
        j+=1
    i+=1
if Nd==1:
    p="YES"
else:
    p="NO"
print(p)