#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <queue>
#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()
using namespace std;
using ll = long long;
template <class T>
using V = vector<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));
	}

	ll ans = 0;
	V<deque<ll> > que(2, deque<ll>({}));
	itrep(itr, xst) {
		ll x = *itr;
		ans += min(x, n - 1) - max(-n + 1 + x, 0ll) + 1;
		que[x & 1].push_back(x);
	}

	V<ll> yv = {};
	itrep(itr, yst) {
		yv.push_back(abs(*itr));
	}
	sort(all(yv));
	for (auto y : yv) {
		ll lv = y, rv = 2 * (n - 1) - y;
		int b = abs(y) & 1;
		ans += min(n - 1 + y, n - 1) - max(y, 0ll) + 1;
		while (que[b].empty() == false and que[b].back() > rv) {
			que[b].pop_back();
		}
		while (que[b].empty() == false and que[b].front() < lv) {
			que[b].pop_front();
		}
		ans -= que[b].size();
	}

	cout << ans << endl;

	return 0;
}