#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

using ull = unsigned long long;
std::mt19937 RNG(std::chrono::system_clock::now().time_since_epoch().count());
unsigned long long RULL() {
  return std::uniform_int_distribution<unsigned long long>()(RNG);
}

ull hs[100010];

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  rep(i, 100010) hs[i] = RULL();
  int n;
  ll mx;
  cin >> mx >> n;
  vector<pair<ll, int>> evs(2 * n + 1);
  rep(i, n) {
    ll l, r;
    cin >> l >> r;
    l--;
    evs[2*i] = {l, i};
    evs[2*i+1] = {r, i};
  }
  evs[2*n] = {mx, 0};
  ull now = 0;
  unordered_map<ll, mint> freq;
  ranges::sort(evs, {}, &pair<ll, int>::first);
  ll pre = 0;
  mint c0;
  for (auto [t, i] : evs) {
    if (pre < t) {
      (now ? freq[now] : c0) += t - pre;
    }
    now ^= hs[i];
    pre = t;
  }
  mint ans;
  mint s1, s2;
  vector<mint> c;
  mint tmp = mint(2).pow(n) / 2;
  mint xx;
  for (auto [_, v] : freq) {
    s1 += v;
    s2 += v * v;
    ans += (v * v) * tmp;
  }
  ans += (s1.pow(2) - s2) * mint(2).pow(n) / 4;
  ans += 2 * c0 * s1 * mint(2).pow(n) / 2;
  ans += c0 * c0 * mint(2).pow(n);
  cout << ans.val() << '\n';
}