#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#define rep(i, l, n) for (int i = (l); i < (n); i++)
#define itrep(itr, st) for(auto itr = st.begin(); itr != st.end(); itr++)
#define all(x) x.begin(), x.end()
#define lb(A, x) (lower_bound(all(A), x) - A.begin())
#define ub(A, x) (upper_bound(all(A), x) - A.begin())
using namespace std;
using ll = long long;
template <class T>
using V = vector<T>;
template <class T>
using VV = V<V<T> >;


int main(void) {
	ll n, m;	cin >> n >> m;

	set<ll> xst = {}, yst = {};
	rep(i, 0, m) {
		ll X, Y;	cin >> X >> Y;
		xst.insert((X - 1) + (Y - 1));
		yst.insert((X - 1) - (Y - 1));
	}

	VV<ll> xv(2, V<ll>({}));
	itrep(itr, xst) {
		ll x = *itr;
		xv[x & 1].push_back(x);
	}

	ll ans = 0;
	itrep(itr, xst) {
		ll x = *itr;
		ans += min(x, n - 1) - max(-n + 1 + x, (ll)0) + 1;
	}
	itrep(itr, yst) {
		ll y = *itr;	int b = abs(y) & 1;
		ans += min(n - 1 + y, n - 1) - max(y, (ll)0) + 1;
		auto l = lb(xv[b], max(y, -y));
		auto r = ub(xv[b], min(2 * (n - 1) - y, 2 * (n - 1) + y));
		ans -= r - l;
	}

	cout << ans << endl;

	return 0;
}