#include <bits/stdc++.h>
using namespace std;
//*
#include <atcoder/all>
using namespace atcoder;
//using mint = modint998244353;
using mint = modint1000000007;
//*/
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {ll res = A % M; if (res < 0) res += M; return res;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
ll mypowl(ll A, ll B) {ll res = 1; for (int i = 0; i < B; i++) {res *= A;} return res;}
template<class T> void unique(vector<T> &V) {V.erase(unique(V.begin(), V.end()), V.end());}
template<class T> void sortunique(vector<T> &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)
template<class T> void printvec(const vector<T> &V) {int _n = V.size(); for (int i = 0; i < _n; i++) cout << V[i] << (i == _n - 1 ? "" : " ");cout << '\n';}
template<class T> void printvect(const vector<T> &V) {for (auto v : V) cout << v << '\n';}
template<class T> void printvec2(const vector<vector<T>> &V) {for (auto &v : V) printvec(v);}

int main()
{
  ll N, M;
  cin >> N >> M;
  vector<ll> X(M), Y(M);
  for (ll i = 0; i < M; i++)
  {
    cin >> X.at(i) >> Y.at(i);
  }

  vector<ll> A, B;
  for (ll i = 0; i < M; i++)
  {
    ll x = X.at(i), y = Y.at(i);
    A.push_back(y - x), B.push_back(y + x);
  }
  sortunique(A), sortunique(B);

  ll ans = 0;
  for (auto a : A)
  {
    ll l = max(1LL, 1 - a), r = min(N, N - a);
    ans += r - l + 1;
  }
  for (auto b : B)
  {
    ll l = max(1LL, b - N), r = min(N, b - 1);
    ans += r - l + 1;
  }

  vector<ll> B0, B1;
  for (auto b : B)
  {
    if (b % 2 == 0)
      B0.push_back(b);
    else
      B1.push_back(b);
  }
  for (auto a : A)
  {
    auto &B2 = (a % 2 == 0 ? B0 : B1);
    ll l = lower_bound(B2.begin(), B2.end(), max(2 - a, 2 + a)) - B2.begin();
    ll r = upper_bound(B2.begin(), B2.end(), min(2 * N - a, 2 * N + a)) - B2.begin();
    ans -= r - l;
  }
  cout << ans << endl;
}