#include<bits/stdc++.h>
#define rep(i,s,n) for (int i = (int)(s); i < (int)(n); i++)
#define reb(i,s,n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) begin(v), end(v)
using namespace std;
using ll = long long;
bool chmin(auto &a, auto b) { return a > b ? a = b, 1 : 0; }
bool chmax(auto &a, auto b) { return a < b ? a = b, 1 : 0; }

template<typename T>
ostream &operator<<(ostream &os, const vector<T> &a){
    if (a.empty()) return os;
    os << a.front();
    for (auto e : a | views::drop(1)){
        os << ' ' << e;
    }
    return os;
}

void dump(auto ...vs){
    ((cout << vs << ' '), ...) << endl;
}

#include<atcoder/modint>
using mint = atcoder::modint998244353;

void solve(){
    ll n; cin >> n;
    int m; cin >> m;
    vector<ll> ls(m), rs(m);
    vector<ll> cp; cp.reserve(m*2);
    rep(i,0,m){
        ll l, r; cin >> l >> r; l--;
        ls[i] = l;
        rs[i] = r;
        cp.emplace_back(l);
        cp.emplace_back(r);
    }
    cp.emplace_back(0);
    cp.emplace_back(n);
    sort(all(cp));
    cp.erase(unique(all(cp)),cp.end());
    int sz = cp.size();
    auto idx = [&](ll x){
        int id = lower_bound(all(cp),x) - cp.begin();
        assert(0 <= id && id < sz);
        assert(cp[id] == x);
        return id;
    };
    random_device rd;
    mt19937_64 mt(rd());
    vector<uint64_t> imos(sz);
    rep(i,0,m){
        int il = idx(ls[i]);
        int ir = idx(rs[i]);
        uint64_t h = mt();
        imos[il] += h;
        imos[ir] -= h;
    }
    unordered_map<uint64_t,mint> mp;
    mint ans = 0, sum = 0;
    rep(i,0,sz-1){
        imos[i+1] += imos[i];
        if (imos[i] > 0){
            mint len = cp[i+1] - cp[i];
            mp[imos[i]] += len;
            sum += len;
        }
    }
    for (auto [h, s] : mp){
        ans += s * s;
    }
    ans += sum * sum;
    ans /= 4;
    ans += n * (n - sum);
    ans *= mint(2).pow(m);
    cout << ans.val() << '\n';
}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    solve();
}