#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define fast cin.tie(nullptr); ios_base::sync_with_stdio(false)
using namespace std;
using ll = long long;
using ull = unsigned long long;
constexpr ll mod = 998244353;

struct Event{
    ll pos;
    ll type;
    ll idx;
    bool operator<(const Event &e) const {
        if(pos != e.pos) return pos < e.pos;
        return type < e.type;
    }
};

void zobrist_init(vector<ull> &a){
    mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
    for(int i = 0; i < a.size(); i++) a[i] = rng();
}
int main(){
	fast;
    ll n,m,l,r,two_pow = 748683265;// 4^{-1} mod 998244353
    vector<Event> events;
    cin >> n >> m;
    for(int i = 0; i < m; i++){
        cin >> l >> r;
        events.push_back({l, 0, i});
        events.push_back({r + 1, 1, i});
        two_pow = (two_pow << 1) % mod;
    }
    vector<ull> zobrist(m + 1);
    zobrist_init(zobrist);
    sort(all(events));

    map<ull,ll> t;
    ll last = 1;
    ull hash = 0;
    for(auto&e : events){
        ll now = e.pos;
        if(now > last) t[hash] = (t[hash] + (now - last)) % mod;
        hash ^= zobrist[e.idx];
        last = now;
    }
    if(last <= n) t[hash] = (t[hash] + (n - last + 1)) % mod;
    ll n0 = t[0],p = 0;
    for(auto&[h,w] : t){
        if(h) p = (p + w * (w - 1)) % mod;
    }
    ll ans = ((n + n0) % mod) % mod;
    ans = (ans * ((n + n0) % mod)) % mod;
    ans = (ans + n + p - n0) % mod;
    ans = (ans * two_pow) % mod;
    cout << ans << endl;
}