package main

import (
  "bufio"
  "os"
  "strconv"
  "strings"
  "fmt"
)

type Evaluator func(a, b interface{}) interface{}
func Eval(a, b interface{}) interface{} {
  x := a.(int)
  y := b.(int)
  if x < y { return b }
  return a
} 
type SegmentTree struct {
  size  int
  data  []interface{}
  inf   interface{}
  eval  Evaluator
}
func InitSegmentTree(N int, inf interface{}, eval Evaluator) *SegmentTree {
  size := 1
  for size < N {
    size *= 2
  }
  S := make([]interface{}, size * 2)
  for i := range S {
    S[i] = inf
  }
  return &SegmentTree{
    size: size,
    data: S,
    inf:  inf,
    eval: eval,
  }
}
func (ST *SegmentTree) Update(index int, value interface{}) {
  idx := ST.size + index
  ST.data[idx] = value
  for idx > 1 {
    parent := idx / 2
    ST.data[parent] = ST.eval(ST.data[2 * parent], ST.data[2 * parent + 1])
    idx = parent
  }
}
func (ST *SegmentTree) Get(from, to, index, left, right int) interface{} {
  // get [from, to)
  if to <= left || right <= from { return ST.inf }
  if from <= left && right <= to { return ST.data[index] }
  m := (left + right) / 2
  lval := ST.Get(from, to, 2 * index, left, m)
  rval := ST.Get(from, to, 2 * index + 1, m, right)
  return ST.eval(lval, rval)
}
func (ST *SegmentTree) Query(from, to int) interface{} {
  return ST.Get(from, to, 1, 0, ST.size)
}

func Solve() {
  var N, Q, p, x int
  NextInt(&N, &Q)
  B := (N - 2) * (N - 2)
  XY := make([][]int, 2)
  for i := range XY {
    XY[i] = make([]int, N)
    for j := range XY[i] { XY[i][j] = N }
  }
  ST := make([]*SegmentTree, 2)
  for i := range ST {
    ST[i] = InitSegmentTree(N, 0, Eval)
    ST[i].Update(1, 1)
  }
  for i := 0; i < Q; i++ {
    NextInt(&p, &x)
    p--
    j := ST[p].Query(1, x).(int)
    b := XY[p][j]
    B -= b - 2
    XY[p][x] = b
    ST[p].Update(x, x)
    XY[1 - p][1] = MinInt(XY[1 - p][1], x)
  }
  Write(B)
}

func main() {
  Solve()
  Output()
}

var reader = bufio.NewReaderSize(os.Stdin, 1000000)
var writer = bufio.NewWriter(os.Stdout)
func NextLine() string {
  buffer := make([]byte, 0)
  for true {
    line, isPrefix, err := reader.ReadLine()
    if err != nil { panic(err) }
    buffer = append(buffer, line...)
    if !isPrefix { break }
  }
  return string(buffer)
}
func NextInt(A ...*int) {
  L := strings.Split(NextLine(), " ")
  for i, a := range A {
    *a, _ = strconv.Atoi(L[i])
  }
}
func NextIntSlice(A *[]int) {
  L := strings.Split(NextLine(), " ")
  if len(L) == 1 && L[0] == "" {
    (*A) = make([]int, 0)
    return
  }
  (*A) = make([]int, len(L))
  for i, l := range L {
    (*A)[i], _ = strconv.Atoi(l)
  }
}
func NextFloat(A ...*float64) {
  L := strings.Split(NextLine(), " ")
  for i, a := range A {
    *a, _ = strconv.ParseFloat(L[i], 64)
  }
}
func NextFloatSlice(A *[]float64) {
  L := strings.Split(NextLine(), " ")
  if len(L) == 1 && L[0] == "" {
    (*A) = make([]float64, 0)
    return
  }
  (*A) = make([]float64, len(L))
  for i, l := range L {
    (*A)[i], _ = strconv.ParseFloat(l, 64)
  }
}
func Write(S ...interface{}) {
  fmt.Fprintln(writer, S...)
}
func WriteIntSlice(A []int) {
  B := make([]interface{}, len(A))
  for i, a := range A { B[i] = a }
  fmt.Fprintln(writer, B...)
}
func Output() {
  _ = writer.Flush()
}
func MaxInt(A ...int) int {
  max := A[0]
  for _, a := range A {
    if max < a { max = a }
  }
  return max
}
func MinInt(A ...int) int {
  min := A[0]
  for _, a := range A {
    if a < min { min = a }
  }
  return min
}
func SumInt(A ...int) int {
  sum := 0
  for _, a := range A {
    sum += a
  }
  return sum
}
func AbsInt(x int) int {
  if x < 0 { x = -x }
  return x
}


Measured memory_bytes: 34500