#include <bits/stdc++.h>
const int N = 200200;
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int Q = 400200;
const int mod = 998244353;
int pw(int x, int n) {
  int res = 1;
  for (; n > 0; n >>= 1) {
    if (n & 1) {
      res = 1ll * res * x % mod;
    }
    x = 1ll * x * x % mod;
  }
  return res;
}
int fac[Q], inv[Q];
void make() {
  fac[0] = 1;
  for (int i = 1; i < Q; i++) fac[i] = fac[i - 1] * 1ll * i % mod;
  inv[Q - 1] = pw(fac[Q - 1], mod - 2);
  for (int i = Q - 2; i >= 0; i--) inv[i] = 1ll * inv[i + 1] * (i + 1) % mod;
}
int C(int n, int k) {
  if (k < 0 || k > n) return 0;
  return 1ll * fac[n] * inv[k] % mod * inv[n - k] % mod;
}
void add(int &x, int y) {
  x += y;
  if (x >= mod) x -= mod;
}
void sub(int &x, int y) {
  x -= y;
  if (x < 0) x += mod;
}
struct treap {
  treap *l, *r;
  int x, y, delta;
  treap(int _x) {
    l = r = NULL;
    x = _x;
    y = rng();
    delta = 0;
  }
};
typedef treap *tree;
tree root;
void push(tree v) {
  if (v == NULL || v->delta == 0) {
    return;
  }
  if (v->l != NULL) {
    v->l->x += v->delta;
    v->l->delta += v->delta;
  }
  if (v->r != NULL) {
    v->r->x += v->delta;
    v->r->delta += v->delta;
  }
  v->delta = 0;
}
void split(tree v, tree &l, tree &r, int x) {
  if (v == NULL) {
    l = r = NULL;
    return;
  }
  push(v);
  if (v->x <= x) {
    split(v->r, v->r, r, x);
    l = v;
  } else {
    split(v->l, l, v->l, x);
    r = v;
  }
}
tree merg(tree l, tree r) {
  if (l == NULL || r == NULL) {
    return l == NULL ? r : l;
  }
  push(l);
  push(r);
  if (l->y > r->y) {
    l->r = merg(l->r, r);
    return l;
  } else {
    r->l = merg(l, r->l);
    return r;
  }
}
void prnt(tree v) {
  if (v == NULL) {
    return;
  }
  prnt(v->l);
  cout << v->x << " ";
  prnt(v->r);
}
int n, m;
int X[N];
int id[N];
int b[N];
int t[N];
void solve() {
  root = NULL;
  cin >> n >> m;
  int res = 2 * n - 1 - m;
  for (int i = 1; i <= m; i++) {
    int x, y;
    cin >> x >> y;
    y -= 1;
    tree a, b, c;
    split(root, a, c, y);
    split(a, a, b, y - 1);
    if (c != NULL) {
      c->delta += 1;
      c->x += 1;
    }
    if (b != NULL) {
      res += 1;
    }
    b = new treap(y + 1);
    root = merg(a, merg(b, c));
  }
  cout << C(res, n) << "\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  make();
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
}
