#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
#define fi first
#define se second
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = 0;
//---------------------------------//

#include <vector>
#include <cassert>
#include <functional>

template<typename T, typename E>
struct LazySegmentTree {
	using value_type = T;
	using lazy_type = E;
	using size_type = std::size_t;
	using F = std::function<value_type(const value_type &, const value_type &)>; // 要素の merge
	using G = std::function<value_type(const value_type &, const lazy_type &)>; // 要素に作用素を作用
	using H = std::function<lazy_type(const lazy_type &, const lazy_type &)>; // 作用素の merge
	using P = std::function<lazy_type(const lazy_type &, size_type)>; // 区間への作用がその区間の大きさ(k) に比例して変化するとき p(a, k) := g(a, a, ..., a) (k 個)
	
private:
	size_type n, n_, n_log;
	value_type id_node;
	lazy_type id_lazy;
	F f;
	G g;
	H h;
	P p;
	std::vector<value_type> node;
	std::vector<lazy_type> lazy;

public:
	LazySegmentTree(size_type n, const value_type & id_node, const lazy_type & id_lazy, const F & f, const G & g, const H & h, const P & p = [](const lazy_type & a, size_type l) { return a; })
			: n(n), id_node(id_node), id_lazy(id_lazy), f(f), g(g), h(h), p(p) {
		n_ = 1;
		n_log = 0;
		while (n_ < n) n_ <<= 1, ++n_log;
		node.resize(2 * n_, id_node);
		lazy.resize(2 * n_, id_lazy);
	}
	
	LazySegmentTree(const std::vector<value_type> & v, const value_type & id_node, const lazy_type & id_lazy, const F & f, const G & g, const H & h, const P & p = [](const lazy_type & a, size_type l) { return a; })
			: LazySegmentTree(v.size(), id_node, id_lazy, f, g, h, p) {
		for (size_type i = 0; i < v.size(); ++i) node[i + n_] = v[i];
		for (size_type i = n_ - 1; i > 0; --i) node[i] = f(node[i << 1], node[i << 1 | 1]);
	}
	
	size_type size() const noexcept {
		return n;
	}
	
	void set(size_type k, const value_type & x) {
		assert(k < size());
		k += n_;
		thrust(k);
		node[k] = x;
		lazy[k] = id_lazy;
		recalc(k);
	}
	
	value_type get(size_type k) {
		assert(k < size());
		k += n_;
		thrust(k);
		return reflect(k, 1);
	}
	
	void update(size_type l, size_type r, const lazy_type & x) {
		assert(l <= r);
		assert(r <= size());
		if (l == r) return;
		l += n_;
		r += n_;
		thrust(l);
		thrust(r - 1);
		for(size_type cl = l, cr = r; cl < cr; cl >>= 1, cr >>= 1) {
			if (cl & 1) lazy[cl] = h(lazy[cl], x), ++cl;
			if (cr & 1) --cr, lazy[cr] = h(lazy[cr], x);
		}
		recalc(l);
		recalc(r - 1);
		return;
	}
	
	value_type fold(size_type l, size_type r) {
		assert(l <= r);
		assert(r <= size());
		if (l == r) return id_node;
		l += n_;
		r += n_;
		thrust(l);
		thrust(r - 1);
		value_type vl = id_node, vr = id_node;
		for (size_type w = 1; l < r; l >>= 1, r >>= 1, w <<= 1) {
			if (l & 1) vl = f(vl, reflect(l, w)), ++l;
			if (r & 1) --r, vr = f(reflect(r, w), vr);
		}
		return f(vl, vr);
	}
	
	value_type fold_all() const {
		return node[1];
	}
	
private:
	value_type reflect(size_type k, size_type w) {
		return lazy[k] == id_lazy ? node[k] : g(node[k], p(lazy[k], w));
	}
	
	void propagate(size_type k, size_type w) {
		if (lazy[k] == id_lazy) return;
		if ((k << 1 | 1) < node.size()) {
			lazy[k << 1] = h(lazy[k << 1], lazy[k]);
			lazy[k << 1 | 1] = h(lazy[k << 1 | 1], lazy[k]);
		}
		node[k] = reflect(k, w); // g(node[k], p(lazy[k], l));
		lazy[k] = id_lazy;
	}
	
	void recalc(size_type k) {
		for (size_type i = k >> 1, cw = 1; i > 0; i >>= 1, cw <<= 1)
			node[i] = f(reflect(i << 1, cw), reflect(i << 1 | 1, cw));
	}
	
	void thrust(size_type k) {
		for (size_type i = n_log, w = n_; i > 0; --i, w >>= 1) propagate(k >> i, w);
	}
};

int main() {
	int N, Q;
	cin >> N >> Q;
	
	LazySegmentTree<int, int> col(N, N - 1, INF,
		[](auto && x, auto && y) { return x < y ? x : y; },
		[](auto && x, auto && y) { return y; },
		[](auto && x, auto && y) { return y; });
	auto row = col;
	
	ll black = (ll)(N - 2) * (N - 2);
	int jmin = N, imin = N;
	while (Q--) {
		int q, x;
		scanf("%d %d", &q, &x); --x;
		if (q == 1) {
			// j = x
			int mx = row.get(x);
			black -= mx - 1;
			if (chmin(jmin, x)) col.update(0, mx, x);
		}
		else {
			// i = x
			int mx = col.get(x);
			black -= mx - 1;
			if (chmin(imin, x)) row.update(0, mx, x);
		}
	}
	cout << black << endl;
	return 0;
}


Measured memory_bytes: 11428