#include <bits/stdc++.h>
#define itrep(itr, st) for(auto itr = st.begin(); itr != st.end(); itr++)
#define all(x) x.begin(), x.end()
#define lb(A, x) (lower_bound(all(A), x) - A.begin())
#define ub(A, x) (upper_bound(all(A), x) - A.begin())
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));
    }

    vector<vector<ll> > xvec(2, vector<ll>({}));
    itrep(itr, xst){
        ll x = *itr;
        xvec[x & 1].push_back(x);
    }

    ll ans = 0;
    itrep(itr, xst){
        ll x = *itr;
        ans += min(x, n - 1) - max(x - (n - 1), (ll)0) + 1;
    }
    itrep(itr, yst){
        ll y = *itr;    int b = y & 1;
        ans += min(n - 1 + y, n - 1) - max(y, (ll)0) + 1;
        auto l = lb(xvec[b], abs(y));
        auto r = ub(xvec[b], 2 * (n - 1) - abs(y));
        ans -= r - l;
    }
    cout << ans << endl;

    return 0;
}