#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

struct combi{
	deque<mint> kaijou;
	deque<mint> kaijou_;
	
	combi(int n){
		kaijou.push_back(1);
		for(int i=1;i<=n;i++){
			kaijou.push_back(kaijou[i-1]*i);
		}
		
		mint b=kaijou[n].inv();
		
		kaijou_.push_front(b);
		for(int i=1;i<=n;i++){
			int k=n+1-i;
			kaijou_.push_front(kaijou_[0]*k);
		}
	}
	
	mint combination(int n,int r){
		if(r>n)return 0;
		mint a = kaijou[n]*kaijou_[r];
		a *= kaijou_[n-r];
		return a;
	}
	
	mint junretsu(int a,int b){
		mint x = kaijou_[a]*kaijou_[b];
		x *= kaijou[a+b];
		return x;
	}
	
	mint catalan(int n){
		return combination(2*n,n)/(n+1);
	}
	
};
combi C(300000);

int main(){
	
	int n,q;
	cin>>n>>q;
	
	vector<int> l(q),r(q);
	rep(i,q){
		cin>>l[i]>>r[i];
		l[i]--;
	}
	
	mint ans = 1;
	
	ans *= C.kaijou[n/2];
	ans *= C.kaijou[(n+1)/2];
	
	l.push_back(0);
	if(n%2==1){
		n++;
	}
	r.push_back(n);
	
	vector<long long> imos(n+1,0);
	rep(i,l.size()){
		for(int j=l[i];j<r[i];j++)imos[j] |= 1LL<<i;
	}
	map<long long,int> mp;
	rep(i,n){
		mp[imos[i]]++;
	}
	for(auto a:mp){
		if(a.second%2==1)ans = 0;
		else ans *=C.catalan(a.second/2);
	}
	
	cout<<ans.val()<<endl;
	
	return 0;
}