#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	long long n, m; cin >> n >> m;
	vector<long long>sx(m), sy(m);
	rep(i, m) {
		long long x, y; cin >> x >> y;
		x--, y--;
		sx[i] = x + y;
		sy[i] = x - y;
	}
	sort(all(sx));
	sx.erase(unique(all(sx)), sx.end());
	sort(all(sy));
	sy.erase(unique(all(sy)), sy.end());
	long long ans = 0;
	vector<vector<long long>>sysub(2);
	for (auto e : sy) sysub[abs(e) % 2].push_back(e);
	for (auto e : sx) {
		long long mn, mx;
		if (e < n) mn = 0, mx = e;
		else mn = e - (n - 1), mx = n - 1;
		ans += mx - mn + 1;
		ans -= upper_bound(all(sysub[abs(e - mn * 2) % 2]), e - mn * 2)
			- lower_bound(all(sysub[abs(e - mn * 2) % 2]), e - mx * 2);
	}
	for (auto e : sy) {
		long long mn, mx;
		if (e <= 0) mn = -e, mx = n - 1;
		else mn = 0, mx = (n - 1) - e;
		ans += mx - mn + 1;
	}
	cout << ans << endl;
	return 0;
}