#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------


ll N,M;
ll L,R;
const ll mo=998244353;

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>M;
	map<ll,ll> ev;
	FOR(i,M) {
		cin>>L>>R;
		L--;
		ll hash=((rand()%(1LL<<30))<<30)+(rand()%(1<<30));
		ev[L]^=hash;
		ev[R]^=hash;
	}
	ll preh=ev[0];
	ll pre=0;
	ev[N]^=0;
	map<ll,ll> count;
	ll P=0;
	FORR2(a,b,ev) if(a) {
		ll num=a-pre;
		if(preh) {
			P+=1LL*(count[preh]%mo)*(num%mo)%mo;
			P+=1LL*(num%mo)*((num-1)%mo)%mo*((mo+1)/2)%mo;
		}
		count[preh]+=num;
		pre=a;
		preh^=b;
	}
	
	ll N0=count[0];
	ll ret=((N+N0)%mo*((N+N0)%mo)%mo+N%mo+mo-N0%mo+2*P)%mo;
	FOR(i,M-2) ret=2*ret%mo;
	cout<<ret<<endl;
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}