#include <bits/stdc++.h>
using namespace std;
struct debugger {
  template <typename T>
  debugger& operator,(const T& v) {
    cerr << v << " ";
    return *this;
  }
} dbg;
inline long long gcd(long long a, long long b) {
  a = ((a) < 0 ? -(a) : (a));
  b = ((b) < 0 ? -(b) : (b));
  while (b) {
    a = a % b;
    swap(a, b);
  }
  return a;
}
long long ext_gcd(long long A, long long B, long long* X, long long* Y) {
  long long x2, y2, x1, y1, x, y, r2, r1, q, r;
  x2 = 1;
  y2 = 0;
  x1 = 0;
  y1 = 1;
  for (r2 = A, r1 = B; r1 != 0;
       r2 = r1, r1 = r, x2 = x1, y2 = y1, x1 = x, y1 = y) {
    q = r2 / r1;
    r = r2 % r1;
    x = x2 - (q * x1);
    y = y2 - (q * y1);
  }
  *X = x2;
  *Y = y2;
  return r2;
}
inline long long modInv(long long a, long long m) {
  long long x, y;
  ext_gcd(a, m, &x, &y);
  x %= m;
  if (x < 0) x += m;
  return x;
}
inline long long bigmod(long long a, long long p, long long m) {
  long long res = 1 % m, x = a % m;
  while (p) {
    if (p & 1) res = (res * x) % m;
    x = (x * x) % m;
    p >>= 1;
  }
  return res;
}
int ext_euclid(int a, int b, int& x, int& y) {
  x = 1, y = 0;
  int x1 = 0, y1 = 1, a1 = a, b1 = b;
  while (b1) {
    int q = a1 / b1;
    tie(x, x1) = make_tuple(x1, x - q * x1);
    tie(y, y1) = make_tuple(y1, y - q * y1);
    tie(a1, b1) = make_tuple(b1, a1 - q * b1);
  }
  return a1;
}
long long int binpow(long long int a, long long int b, long long int m) {
  a %= m;
  long long int res = 1;
  while (b > 0) {
    if (b & 1) res = res * a % m;
    a = a * a % m;
    b >>= 1;
  }
  return res;
}
const long long inf = 2147383647;
const long long mod = 1000000007;
const double pi = 2 * acos(0.0);
const double eps = 1e-11;
long long int bin_search(long long int* array, long long int low,
                         long long int high, long long int search) {
  while (low != high) {
    long long int mid = (low + high) / 2;
    if (array[mid] == search) {
      return mid;
    }
    if (array[mid] <= search) {
      low = mid + 1;
    } else {
      high = mid;
    }
  }
  return low;
}
long long int countWays(long long int arr[], long long int m, long long int n) {
  long long int count[n + 1];
  memset(count, 0, sizeof(count));
  count[0] = 1;
  for (long long int i = 0; i < n + 1; i++) {
    for (long long int j = 0; j < m; j++) {
      if (i >= arr[j]) {
        count[i] += count[i - arr[j]];
      }
    }
  }
  return count[n - 1];
}
const long long int md = 998244353;
const long long int MXN = 1e5 + 1;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int n, k, a, b;
  cin >> n >> k;
  set<long long int> s1;
  for (long long int i = 0; i < k; i++) {
    cin >> a >> b;
    for (long long int j = a; j <= b; j++) {
      s1.insert(j);
    }
  }
  long long int index = 0;
  long long int arr[100000];
  for (auto i : s1) {
    arr[index] = i;
    index++;
  }
  long long int g = countWays(arr, index, n) % md;
  cout << g;
  return 0;
}
