#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const long long INF64 = 0x3f3f3f3f3f3f3f3f;
const double PI = acos(-1);
typedef std::priority_queue<int, vector<int>, greater<int>> small_pq;
typedef std::priority_queue<int, vector<int>, less<int>> big_pq;
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<
                                    !is_same<T_container, string>::value,
                                    typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v) {
  os << '{';
  string sep;
  for (const T &x : v) os << sep << x, sep = ", ";
  return os << '}';
}
void dbg_out() {}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
  cerr << " " << H;
  if (sizeof...(T) > 0) cerr << " ,";
  dbg_out(T...);
}
void dbg_name(const string &s) {
  string ss = s;
  replace(ss.begin(), ss.end(), ',', ' ');
  cerr << "  ( " << ss << " )  ";
}
template <typename T>
inline void setmin(T &a, const T &b) {
  if (b < a) a = b;
}
template <typename T>
inline void setmax(T &a, const T &b) {
  if (b > a) a = b;
}
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }
  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
unordered_map<long long, int, custom_hash> safe_map;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rnd64(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 998244353;
int mul(int x, int y) { return 1ll * x * y % MOD; }
int add(int x, int y) { return ((x + y) % MOD + MOD) % MOD; }
int sub(int x, int y) { return ((x - y) % MOD + MOD) % MOD; }
int qpow(int a, int b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = mul(ans, a);
    a = mul(a, a);
    b /= 2;
  }
  return ans;
}
const int N = 6e5 + 5;
struct BitTree {
  const static int R = N;
  int a[R];
  void add(int pos, int x) {
    while (pos < R) {
      a[pos] += x;
      pos += ((-(pos)) & (pos));
    }
  }
  int sum(int pos) {
    int ans = 0;
    while (pos) {
      ans += a[pos];
      pos -= ((-(pos)) & (pos));
    }
    return ans;
  }
  int kth(int k) {
    int now = 0;
    for (int i = 18; i >= 0; i--) {
      if (a[now + (1 << i)] < k) {
        k -= a[now + (1 << i)];
        now += 1 << i;
      }
    }
    return now + 1;
  }
} bt;
int fac[N], inv[N];
int x[N], y[N];
int C(int n, int m) {
  if (n < 0 || m < 0 || n < m) return 0;
  return mul(fac[n], mul(inv[m], inv[n - m]));
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  fac[0] = 1;
  for (int(i) = int(1); int(i) <= int(N - 1); i++) fac[i] = mul(i, fac[i - 1]);
  inv[N - 1] = qpow(fac[N - 1], MOD - 2);
  for (int(i) = int(N - 2); int(i) >= int(0); i--)
    inv[i] = mul(inv[i + 1], i + 1);
  for (int(i) = int(1); int(i) <= int(N - 1); i++) bt.add(i, 1);
  int t;
  cin >> t;
  while (t--) {
    int n, m;
    cin >> n >> m;
    for (int(i) = int(1); int(i) <= int(m); i++) cin >> x[i] >> y[i];
    vector<int> pos(m + 1);
    int cnt = 0;
    for (int(i) = int(m); int(i) >= int(1); i--) {
      pos[i] = bt.kth(y[i]);
      if (bt.sum(pos[i] + 1) - bt.sum(pos[i])) cnt++;
      bt.add(pos[i], -1);
    }
    int ans = C(2 * n - 1 - cnt, n);
    cout << ans << endl;
    for (int(i) = int(1); int(i) <= int(m); i++) {
      bt.add(pos[i], 1);
    }
  }
  return 0;
}
