local mfl, mce = math.floor, math.ceil
local mmi, mma = math.min, math.max
local bls, brs = bit.lshift, bit.rshift
local LazyRangeSeg = {}
LazyRangeSeg.create = function(self, n, func)
  local stagenum, mul = 1, 1
  self.func = func
  self.n = n
  self.stage = {{n}}
  self.lazy = {{n}}
  while mul < n do
    mul, stagenum = mul * 2, stagenum + 1
    self.stage[stagenum] = {}
    self.lazy[stagenum] = {}
    for i = 1, mul do
      self.stage[stagenum][i] = n
      self.lazy[stagenum][i] = n
    end
  end
  self.left_stage = {}
  for i = 1, n do
    local sp, sz = 1, bls(1, stagenum - 1)
    while(i - 1) % sz ~= 0 do
      sp, sz = sp + 1, brs(sz, 1)
    end
    self.left_stage[i] = sp
  end
  self.sz_stage = {}
  local tmp, sp = 1, stagenum
  for i = 1, n do
    if tmp * 2 == i then tmp, sp = tmp * 2, sp - 1 end
    self.sz_stage[i] = sp
  end
  self.stagenum = stagenum
end
LazyRangeSeg.resolve = function(self, right)
  local stagenum = self.stagenum
  local offset = 0
  for i = 1, stagenum - 1 do
    local p = offset + bls(1, stagenum - i)
    if p < right then
      offset = p
      p = p + bls(1, stagenum - i)
    end
    if right < p then
      local curidx = brs(p, stagenum - i)
      local incval = self.lazy[i][curidx]
      if incval < self.n then
        self:resolveRange(i + 1, curidx * 2 - 1, incval, true)
        self:resolveRange(i + 1, curidx * 2, incval, true)
        self.lazy[i + 1][curidx * 2 - 1] = self.func(self.lazy[i + 1][curidx * 2 - 1], incval)
        self.lazy[i + 1][curidx * 2] = self.func(self.lazy[i + 1][curidx * 2], incval)
        self.lazy[i][curidx] = self.n
      end
    elseif p == right then
      break
    else
      assert(false)
    end
  end
end
LazyRangeSeg.resolveRange = function(self, stagepos, idx, value, shallow)
  self.stage[stagepos][idx] = self.func(self.stage[stagepos][idx], value)
  if shallow then return end
  for i = stagepos - 1, 1, -1 do
    local dst = brs(idx + 1, 1)
    local rem = dst * 4 - 1 - idx
    self.stage[i][dst] = self.func(self.stage[i + 1][idx], self.stage[i + 1][rem])
    idx = dst
  end
end
LazyRangeSeg.getRange = function(self, left, right)
  if 1 < left then self:resolve(left - 1) end
  self:resolve(right)
  local stagenum = self.stagenum
  local ret = self.n
  while left <= right do
    local stage = mma(self.left_stage[left], self.sz_stage[right - left + 1])
    local sz = bls(1, stagenum - stage)
    ret = self.func(ret, self.stage[stage][1 + brs(left - 1, stagenum - stage)])
    left = left + sz
  end
  return ret
end
LazyRangeSeg.setRange = function(self, left, right, value)
  if 1 < left then self:resolve(left - 1) end
  self:resolve(right)
  local stagenum = self.stagenum
  while left <= right do
    local stage = mma(self.left_stage[left], self.sz_stage[right - left + 1])
    local sz = bls(1, stagenum - stage)
    local len = right - left + 1
    local idx = 1 + brs(left - 1, stagenum - stage)
    self:resolveRange(stage, idx, value)
    self.lazy[stage][idx] = self.func(self.lazy[stage][idx], value)
    left = left + sz
  end
end
LazyRangeSeg.new = function(n, func)
  local obj = {}
  setmetatable(obj, {__index = LazyRangeSeg})
  obj:create(n, func)
  return obj
end

local n, q = io.read("*n", "*n")
local st_v = LazyRangeSeg.new(n, mmi)
local st_h = LazyRangeSeg.new(n, mmi)
local tot = 0
for iq = 1, q do
  local tp, x = io.read("*n", "*n")
  if tp == 1 then
    local white_row = st_v:getRange(x, x)
    tot = tot + white_row - 2
    if 2 < white_row then
      st_h:setRange(2, white_row - 1, x)
    end
  else
    local white_col = st_h:getRange(x, x)
    tot = tot + white_col - 2
    if 2 < white_col then
      st_v:setRange(2, white_col - 1, x)
    end
  end
end
print((n - 2) * (n - 2) - tot)


Measured memory_bytes: 27752