#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 1000000000000000001
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(1000000);

int main(){
	
	int n,m;
	cin>>n>>m;
	queue<vector<mint>> Q;
	rep(i,m){
		int l,r;
		cin>>l>>r;
		l--;
		int len = r-l;
		if(len%2)continue;
		len /= 2;
		vector<mint> t(len+1);
		t[0] = 1;
		t[len] = -C.catalan(len);
		Q.push(t);
	}
	Q.push({1});
	while(Q.size()>=2){
		vector<mint> a = Q.front();
		Q.pop();
		auto b = Q.front();
		Q.pop();
		Q.push(convolution(a,b));
	}
	mint ans = 0;
	n /= 2;
	rep(i,Q.front().size()){
		mint t = Q.front()[i];
		t *= C.catalan(n-i);
		ans += t;
	}
	cout<<ans.val()<<endl;
	
	return 0;
}