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

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

//defmodfact
const int COMinitMAX = 998244;
mint fact[COMinitMAX+1], factinv[COMinitMAX+1];

void modfact(){
	fact[0] = 1;
	for (int i=1; i<=COMinitMAX; i++){
		fact[i] = fact[i-1] * i;
	}
	factinv[COMinitMAX] = fact[COMinitMAX].inv();
	for (int i=COMinitMAX-1; i>=0; i--){
		factinv[i] = factinv[i+1] * (i+1);
	}
}

mint cmb(int a, int b){
	if (a<b || b<0) return mint(0);
	return fact[a]*factinv[b]*factinv[a-b];
}
//--------


int main(){
	modfact();

	int n, m; cin >> n >> m;
	vector<int> b(m);
	rep(i,0,m){
		int l, r; cin >> l >> r;
		b[i] = r - l + 1;
	}

	vector<mint> catalan(n+1);
	rep(i,0,n+1){
		catalan[i] = fact[2 * i] * factinv[i + 1] * factinv[i];
	}

	if (n % 2 == 1){
		cout << 0 << '\n';
		return 0;
	}
	deque<vector<mint>> deq;
	rep(i,0,m){
		if (b[i] % 2 == 1){
			continue;
		}
		vector<mint> tar(b[i] / 2 + 1, 0);
		tar[0] = 1;
		tar[b[i] / 2] = - catalan[b[i] / 2];
		deq.push_back(tar);
	}

	while(deq.size() >= 2){
		vector<mint> x = deq.front();
		deq.pop_front();
		vector<mint> y = deq.front();
		deq.pop_front();
		deq.push_back(convolution(x, y));
	}

	vector<mint> x(n + 1);
	if (!deq.empty()) x = deq.front();
	x.resize(n + 1);
	
	mint ans = 0;
	rep(i,0,n/2+1){
		ans += x[i] * catalan[n / 2 - i];
	}
	cout << ans.val() << '\n';

}