#include <bits/stdc++.h>
using namespace std;

#ifdef _RUTHEN
#include "debug.hpp"
#else
#define show(...) true
#endif

using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
template <class T> using V = vector<T>;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll N, M;
    cin >> N >> M;
    show(N, M);
    V<ll> x(M), y(M);
    rep(i, M) {
        cin >> x[i] >> y[i];
        x[i]--, y[i]--;
    }
    show(x, y);
    V<ll> z(M);
    rep(i, M) z[i] = x[i] + y[i];
    sort(z.begin(), z.end());
    z.erase(unique(z.begin(), z.end()), z.end());
    show(z);
    ll ans = 0;
    V<ll> ze, zo;
    for (auto zi : z) {
        // x+y=kの分
        if (zi < N) {
            ans += zi + 1;
        } else {
            ans += 2 * N - 1 - zi;
        }
        if (zi % 2 == 1) {
            zo.push_back(zi);
        } else {
            ze.push_back(zi);
        }
    }
    show(ans);
    V<ll> w(M);
    rep(i, M) w[i] = y[i] - x[i];
    sort(w.begin(), w.end());
    w.erase(unique(w.begin(), w.end()), w.end());
    for (auto wi : w) {
        wi = abs(wi);
        ans += N - wi;
        if (wi % 2 == 1) {
            // zo
            int ind1 = lower_bound(zo.begin(), zo.end(), wi) - zo.begin();
            int ind2 = upper_bound(zo.begin(), zo.end(), 2 * (N - 1) - wi) - zo.begin();
            ans -= ind2 - ind1;
        } else {
            // ze
            int ind1 = lower_bound(ze.begin(), ze.end(), wi) - ze.begin();
            int ind2 = upper_bound(ze.begin(), ze.end(), 2 * (N - 1) - wi) - ze.begin();
            ans -= ind2 - ind1;
        }
    }
    cout << ans << '\n';
    return 0;
}