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

int main(){
	int n,k,ans=0,x1,y1,x2,y2;
	cin>>n>>k;
	short a[n+1][n+1]={0};
	
	for (int i=0;i<k;i++){
		cin>>x1>>y1;
		a[x1][y1]=1;
		x2=1;
		y2=1;
		while(x2<=n){
			a[x2++][y1]=1;
			
		}
		while(y2<=n){
			a[x1][y2++]=1;
		}
	}
	for (int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			if(a[i][j]==1)ans++;
		}
	}
		
	cout<<ans;
	return 0;
}