#pragma GCC optimize("Ofast") 
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) a.size()
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define MOD (ll)(998244353)
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
int main()
{
	int n,q;
	cin>>n>>q;
	vector<ll>a(n+2),b(n+2);
	for(int i=0;i<=n;i++)a[i] = b[i] = n;
	ll ans = (n-2)*1LL*(n-2);
	int h,w;
	h = w = n;
	while(q--){
		int t,x;
		cin>>t>>x;
		if(t == 1){
			if(x<w){
			  for(int i=x;i<w;i++)a[i] = h;
			  w = x;
		    }
			ans-=a[x]-2;
		}else{
			if(x<h){
		       for(int i=x;i<h;i++)b[i] = w;
		       h = x;
		   }
		    ans-=b[x]-2;
		}
	}
	cout<<ans;
}
