#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cout << x; }
void __print(long x) { cout << x; }
void __print(long long x) { cout << x; }
void __print(unsigned x) { cout << x; }
void __print(unsigned long x) { cout << x; }
void __print(unsigned long long x) { cout << x; }
void __print(float x) { cout << x; }
void __print(double x) { cout << x; }
void __print(long double x) { cout << x; }
void __print(char x) { cout << '\'' << x << '\''; }
void __print(const char *x) { cout << '\"' << x << '\"'; }
void __print(const string &x) { cout << '\"' << x << '\"'; }
void __print(bool x) { cout << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cout << '{';
  __print(x.first);
  cout << ',';
  __print(x.second);
  cout << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cout << '{';
  for (auto &i : x) cout << (f++ ? "," : ""), __print(i);
  cout << "}";
}
void _print() { cout << "\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cout << ", ";
  _print(v...);
}
const int mod = 998244353, mxn = 1e5 + 1;
struct fenwick {
  int n;
  vector<int> dat;
  void init(int x) {
    n = x;
    dat.resize(n + 1, 0);
  }
  void update(int ind, int val) {
    ind++;
    while (ind <= n) {
      dat[ind] += val;
      dat[ind] %= mod;
      ind += ind & (-ind);
    }
  }
  int sum(int ind) {
    int sum = 0;
    ind++;
    while (ind > 0) {
      sum += dat[ind];
      sum %= mod;
      ind -= ind & (-ind);
    }
    return sum;
  }
};
int solve() {
  struct fenwick bit;
  bit.init(1e6 + 77);
  int n, k;
  cin >> n >> k;
  vector<int> l(k), r(k);
  for (int i = (0); i < (k); ++i) cin >> l[i] >> r[i];
  vector<int> dp(n + 1, 0);
  dp[1] = 1;
  bit.update(1, 1);
  for (int i = (2); i < (n + 1); ++i) {
    for (int j = (0); j < (k); ++j) {
      if (l[j] >= i) continue;
      int a = l[j], b = r[j];
      b = min(i - 1, b);
      a = min(i + 1, a);
      if (a > b) continue;
      int add = bit.sum(i - a) - bit.sum(i - b - 1);
      dp[i] += add;
      dp[i] %= mod;
      bit.update(i, add);
    }
  }
  cout << dp[n] << "\n";
  return 0;
}
int main() {
  ios_base::sync_with_stdio(NULL);
  cin.tie(NULL);
  cout.tie(NULL);
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
