local mfl, mce = math.floor, math.ceil
local bls, brs = bit.lshift, bit.rshift
local Heapq = {}
Heapq.create = function(self, lt)
  self.lt = lt
  self.cnt = 0
  self.t = {}
end
Heapq.empty = function(self)
  return self.cnt == 0
end

Heapq.push = function(self, v)
  local hqlt = self.lt
  local hqt = self.t
  local c = self.cnt + 1
  self.cnt = c
  hqt[c] = v
  while 1 < c do
    local p = brs(c, 1)
    if hqlt(hqt[c], hqt[p]) then
      hqt[c], hqt[p] = hqt[p], hqt[c]
      c = p
    else
      break
    end
  end
end

Heapq.pop = function(self)
  local hqlt = self.lt
  local hqt = self.t
  local ret = hqt[1]
  local c = self.cnt
  hqt[1] = hqt[c]
  c = c - 1
  self.cnt = c
  local p = 1
  while true do
    local d1, d2 = p * 2, p * 2 + 1
    if c < d1 then break
    elseif c < d2 then
      if hqlt(hqt[d1], hqt[p]) then
        hqt[d1], hqt[p] = hqt[p], hqt[d1]
      end
      break
    else
      if hqlt(hqt[d1], hqt[d2]) then
        if hqlt(hqt[d1], hqt[p]) then
          hqt[d1], hqt[p] = hqt[p], hqt[d1]
          p = d1
        else break
        end
      else
        if hqlt(hqt[d2], hqt[p]) then
          hqt[d2], hqt[p] = hqt[p], hqt[d2]
          p = d2
        else break
        end
      end
    end
  end
  return ret
end

Heapq.new = function(lt)
  local obj = {}
  setmetatable(obj, {__index = Heapq})
  obj:create(lt)
  return obj
end


local h, w = io.read("*n", "*n")
local sr, sc = io.read("*n", "*n")
local added = {}
local a = {}
local v = 0
for i = 1, h do
  for j = 1, w do
    local idx = (i - 1) * w + j
    a[idx] = io.read("*n")
    added[idx] = false
    if i == sr and j == sc then
      v = a[idx]
      added[idx] = true
    end
  end
end

local hq = Heapq.new(function(x, y) return a[x] < a[y] end)
local function walk(src)
  local row = mce(src / w)
  local col = src - (row - 1) * w
  if 1 < row and not added[src - w] then
    added[src - w] = true
    hq:push(src - w)
  end
  if row < h and not added[src + w] then
    added[src + w] = true
    hq:push(src + w)
  end
  if 1 < col and not added[src - 1] then
    added[src - 1] = true
    hq:push(src - 1)
  end
  if col < w and not added[src + 1] then
    added[src + 1] = true
    hq:push(src + 1)
  end
end
walk((sr - 1) * w + sc)
while not hq:empty() do
  local idx = hq:pop()
  -- print(v, a[idx])
  if v <= a[idx] then
    print("No") os.exit()
  end
  walk(idx)
  v = v + a[idx]
end
print("Yes")