#include <bits/stdc++.h>
#define itrep(itr, st) for(auto itr = st.begin(); itr != st.end(); itr++)
using namespace std;
using ll = long long;


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

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

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

	vector<ll> yvec = {};
	itrep(itr, yst) {
		yvec.push_back(abs(*itr));
	}
	sort(yvec.begin(), yvec.end());
	for(auto y : yvec){
		ll lv = y, rv = 2 * (n - 1) - y;
		int b = y & 1;
		ans += min(n - 1 + y, n - 1) - max(y, 0ll) + 1;
		while (!que[b].empty() && que[b].back() > rv) {
			que[b].pop_back();
		}
		while (!que[b].empty() && que[b].front() < lv) {
			que[b].pop_front();
		}
		ans -= que[b].size();
	}
    cout << ans << endl;

    return 0;
}