#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;

constexpr int FACT_SIZE = 1000000;
mint Fact[FACT_SIZE + 1];
mint iFact[FACT_SIZE + 1];
const auto fact_init = [] {
    Fact[0] = mint::raw(1);
    for(int i = 1; i <= FACT_SIZE; ++i) {
        Fact[i] = Fact[i-1] * i;
    }
    iFact[FACT_SIZE] = Fact[FACT_SIZE].inv();
    for(int i = FACT_SIZE; i; --i) {
        iFact[i-1] = iFact[i] * i;
    }
    return false;
}();

mint comb(int n, int k) {
    if (k == 0) return mint::raw(1);
    assert(n >= 0 && k >= 0);
    if (k > n) return mint::raw(0);
    return Fact[n] * iFact[n - k] * iFact[k];
}

mint icomb(int n, int k) {
    return iFact[n] * Fact[n - k] * Fact[k];
}

mint fact(int n) {return Fact[n];}
mint perm(int n, int k) {
    assert(0 <= n);
    return Fact[n] * iFact[n - k];
}

mint f(int len) {
  if (len % 2) return 0;
  if (len == 0) return 1;
  int n = len / 2;
  return comb(2 * n, n) - comb(2 * n, n - 1);
}

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  queue<vector<mint>> q;
  q.push({1});
  rep(_, m) {
    int l, r;
    cin >> l >> r;
    l--;
    vector<mint> g(r - l + 1);
    g[0] = 1;
    g[r - l] = -f(r - l);
    q.emplace(move(g));
  }
  while (q.size() >= 2) {
    auto f = move(q.front()); q.pop();
    auto g = move(q.front()); q.pop();
    q.emplace(convolution(f, g));
  }
  auto h = move(q.front()); q.pop();
  mint ans;
  for (int i = 0; mint v : h) {
    ans += f(n - i) * v;
    // cout << i << ' ' << v.val() << endl;
    i++;
  }
  cout << ans.val() << '\n';
}