#include <iostream>
#include <vector>
#include <set>
#define rep(i, l, n) for (int i = (l); i < (n); i++)
using namespace std;
using ll = long long;
template <class T>
using V = vector<T>;


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

	ll ans = 0;
	V<set<ll> > naname1(2, set<ll>({}));
	V<set<ll> > naname2(2, set<ll>({}));
	rep(i, 0, m) {
		ll x, y;	cin >> x >> y;
		x--;	y--;
		ll p = x - y, q = x + y;
		int b = q & 1;
		if (naname1[b].find(p) == naname1[b].end()) {
			ans += min(n - 1 + p, n - 1) - max(p, (ll)0) + 1;
			auto itr1 = naname2[b].lower_bound(max(p, -p));
			auto itr2 = naname2[b].upper_bound(min(2 * (n - 1) - p, 2 * (n - 1) + p));
			ans -= distance(itr1, itr2);
			naname1[b].insert(p);
		}
		if (naname2[b].find(q) == naname2[b].end()) {
			ans += min(q, n - 1) - max(-n + 1 + q, (ll)0) + 1;
			auto itr1 = naname1[b].lower_bound(max(-q, q - 2 * (n - 1)));
			auto itr2 = naname1[b].upper_bound(min(2 * (n - 1) - q, q));
			ans -= distance(itr1, itr2);
			naname2[b].insert(q);
		}
	}
	cout << ans << endl;

	return 0;
}