#include <bits/stdc++.h>
using ll = long long;
using P = std::pair<ll, ll>;
using namespace std;
constexpr ll INF = 1ll << 60;
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class S, class T>
std::ostream& operator<<(std::ostream& out, const std::pair<S, T>& a) {
  std::cout << '(' << a.first << ", " << a.second << ')';
  return out;
}
template <class T>
std::ostream& operator<<(std::ostream& out, const std::vector<T>& a) {
  std::cout << '[';
  for (ll i = (0); i < (a.size()); ++i) {
    std::cout << a[i];
    if (i != a.size() - 1) std::cout << ", ";
  }
  std::cout << ']';
  return out;
}
const ll mod = 998244353;
struct mint {
  ll x;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}
  mint operator-() const { return mint(-x); }
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod - a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint a) const {
    mint res(*this);
    return res -= a;
  }
  mint operator*(const mint a) const {
    mint res(*this);
    return res *= a;
  }
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1) a *= *this;
    return a;
  }
  mint inv() const { return pow(mod - 2); }
  mint& operator/=(const mint a) { return (*this) *= a.inv(); }
  mint operator/(const mint a) const {
    mint res(*this);
    return res /= a;
  }
  bool operator==(const mint a) const { return this->x == a.x; }
};
template <typename T, typename E>
struct SegmentTree {
  using F = function<T(T, T)>;
  using G = function<T(T, E)>;
  using H = function<E(E, E)>;
  int n, height;
  F f;
  G g;
  H h;
  T ti;
  E ei;
  vector<T> dat;
  vector<E> laz;
  SegmentTree(F f, G g, H h, T ti, E ei) : f(f), g(g), h(h), ti(ti), ei(ei) {}
  void init(int n_) {
    n = 1;
    height = 0;
    while (n < n_) n <<= 1, height++;
    dat.assign(2 * n, ti);
    laz.assign(2 * n, ei);
  }
  void build(const vector<T>& v) {
    int n_ = v.size();
    init(n_);
    for (int i = 0; i < n_; i++) dat[n + i] = v[i];
    for (int i = n - 1; i; i--)
      dat[i] = f(dat[(i << 1) | 0], dat[(i << 1) | 1]);
  }
  inline T reflect(int k) { return laz[k] == ei ? dat[k] : g(dat[k], laz[k]); }
  inline void propagate(int k) {
    if (laz[k] == ei) return;
    laz[(k << 1) | 0] = h(laz[(k << 1) | 0], laz[k]);
    laz[(k << 1) | 1] = h(laz[(k << 1) | 1], laz[k]);
    dat[k] = reflect(k);
    laz[k] = ei;
  }
  inline void thrust(int k) {
    for (int i = height; i; i--) propagate(k >> i);
  }
  inline void recalc(int k) {
    while (k >>= 1) dat[k] = f(reflect((k << 1) | 0), reflect((k << 1) | 1));
  }
  void update(int a, int b, E x) {
    if (a >= b) return;
    thrust(a += n);
    thrust(b += n - 1);
    for (int l = a, r = b + 1; l < r; l >>= 1, r >>= 1) {
      if (l & 1) laz[l] = h(laz[l], x), l++;
      if (r & 1) --r, laz[r] = h(laz[r], x);
    }
    recalc(a);
    recalc(b);
  }
  void set_val(int a, T x) {
    thrust(a += n);
    dat[a] = x;
    laz[a] = ei;
    recalc(a);
  }
  T query(int a, int b) {
    if (a >= b) return ti;
    thrust(a += n);
    thrust(b += n - 1);
    T vl = ti, vr = ti;
    for (int l = a, r = b + 1; l < r; l >>= 1, r >>= 1) {
      if (l & 1) vl = f(vl, reflect(l++));
      if (r & 1) vr = f(reflect(--r), vr);
    }
    return f(vl, vr);
  }
  template <typename C>
  int find(int st, C& check, T& acc, int k, int l, int r) {
    if (l + 1 == r) {
      acc = f(acc, reflect(k));
      return check(acc) ? k - n : -1;
    }
    propagate(k);
    int m = (l + r) >> 1;
    if (m <= st) return find(st, check, acc, (k << 1) | 1, m, r);
    if (st <= l && !check(f(acc, dat[k]))) {
      acc = f(acc, dat[k]);
      return -1;
    }
    int vl = find(st, check, acc, (k << 1) | 0, l, m);
    if (~vl) return vl;
    return find(st, check, acc, (k << 1) | 1, m, r);
  }
  template <typename C>
  int find(int st, C& check) {
    T acc = ti;
    return find(st, check, acc, 1, 0, n);
  }
};
struct combination {
  std::vector<mint> fact, ifact;
  combination(int n) : fact(n + 1), ifact(n + 1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i - 1] * i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i - 1] = ifact[i] * i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n] * ifact[k] * ifact[n - k];
  }
};
ll N, K;
ll L[200010], R[200010];
mint dp[200010], S[200010];
int main() {
  std::cin >> N >> K;
  for (ll i = (0); i < (K); ++i) std::cin >> L[i] >> R[i], ++R[i];
  auto madd = [&](mint a, mint b) { return a + b; };
  SegmentTree<mint, mint> seg(madd, madd, madd, 0, 0);
  seg.init(N + 10);
  seg.set_val(0, 1);
  for (ll i = (0); i < (N); ++i) {
    mint x = seg.query(i, i + 1);
    for (ll j = (0); j < (K); ++j) {
      seg.update(i + L[j], i + R[j], x);
    }
  }
  mint ans = seg.query(N - 1, N);
  std::cout << ans.x << '\n';
  return 0;
}
