#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using ll=long long;
using ld=long double;
ll ILL=2167167167167167167;
const int INF=2100000000;
const ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}


void solve();
// リリリピート
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,t) solve();
}

void solve(){
	ll N,M;
	cin>>N>>M;
	vector<ll> odd,even;
	set<ll> sr,sc;
	rep(i,M){
		ll x,y;
		cin>>x>>y;
		sr.insert(x+y-N-1);
		sc.insert(x-y);
	}
	ll ans=0;
	for(auto x:sr){
		ans+=N-abs(x);
		if(x%2) odd.push_back(x);
		else even.push_back(x);
	}
	for(auto x:sc){
		ans+=N-abs(x);
		ll l,r;
		if((x+(N+1))%2==0){
			l=LB(even,1-N+abs(x));
			r=UB(even,N-1-abs(x));
		}else{
			l=LB(odd,1-N+abs(x));
			r=UB(odd,N-1+abs(x));
		}
		ans-=r-l;
		//cout<<x<<" "<<r<<" "<<l<<"\n";
	}
	cout<<ans<<"\n";
}