local ior = io.input()
local h, w = ior:read("*n", "*n")
local sh, sw, gh, gw = ior:read("*n", "*n", "*n", "*n", "*l")
local str = ""
local map = {}
local state = {}
local function getindex(xh, xw)
  return (xh - 1) * w + xw
end
local cue = {getindex(sh, sw)}
state[getindex(sh, sw)] = true
local tasks, done = 1, 0

local function walk(src, dst)
  if (math.abs(map[src] - map[dst]) <= 1) then
    if(not state[dst]) then
      state[dst] = true
      tasks = tasks + 1
      table.insert(cue, dst)
    end
  end
end
local function ladder(src, mid, dst)
  if(map[src] == map[dst] and map[mid] < map[src]) then
    if(not state[dst]) then
      state[dst] = true
      tasks = tasks + 1
      table.insert(cue, dst)
    end
  end
end

for i = 1, h do
  str = ior:read()
  for j = 1, w do
    local tmp = tonumber(str:sub(j, j))
    local tmp2 = getindex(i, j)
    map[tmp2] = tmp
    state[tmp2] = false
  end
end

while(done < tasks) do
  done = done + 1
  local idx = cue[done]
  if(w < idx) then walk(idx, idx - w) end
  if(idx <= (h - 1) * w) then walk(idx, idx + w) end
  if(idx % w ~= 0) then walk(idx, idx + 1) end
  if(idx % w ~= 1) then walk(idx, idx - 1) end
  if(w * 2 < idx) then ladder(idx, idx - w, idx - 2 * w) end
  if(idx <= (h - 2) * w) then ladder(idx, idx + w, idx + 2 * w) end
  if(idx % w ~= 0 and idx % w ~= (w - 1)) then ladder(idx, idx + 1, idx + 2) end
  if(idx % w ~= 1 and idx % w ~= 2) then ladder(idx, idx - 1, idx - 2) end
end
print(state[getindex(gh, gw)] and "YES" or "NO")