#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rep1(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < (t); ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define em emplace
#define pob pop_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define newline puts("")
#define vc vector
using namespace std;
template<class T> using vv = vc<vc<T>>;
template<class T> using PQ = priority_queue<T,vc<T>,greater<T>>;
using uint = unsigned; using ull = unsigned long long;
using vi = vc<int>; using vvi = vv<int>; using vvvi = vv<vi>;
using ll = long long; using vl = vc<ll>; using vvl = vv<ll>; using vvvl = vv<vl>;
using P = pair<int,int>; using vp = vc<P>; using vvp = vv<P>; using LP = pair<ll,ll>;
int geti(){int x;scanf("%d",&x);return x;}
vi pm(int n, int s=0) { vi a(n); iota(rng(a),s); return a;}
template<class T1,class T2>istream& operator>>(istream&i,pair<T1,T2>&v){return i>>v.fi>>v.se;}
template<class T1,class T2>ostream& operator<<(ostream&o,const pair<T1,T2>&v){return o<<v.fi<<","<<v.se;}
template<class T>istream& operator>>(istream&i,vc<T>&v){rep(j,sz(v))i>>v[j];return i;}
template<class T>string join(const T&v,const string&d=""){stringstream s;rep(i,sz(v))(i?s<<d:s)<<v[i];return s.str();}
template<class T>ostream& operator<<(ostream&o,const vc<T>&v){if(sz(v))o<<join(v," ");return o;}
template<class T>void vin(vc<T>&a){int n;cin>>n;a=vc<T>(n);cin>>a;}
template<class T>void vin(vv<T>&a){int n,m;cin>>n>>m;a=vv<T>(n,vc<T>(m));cin>>a;}
template<class T1,class T2>void operator--(pair<T1,T2>&a,int){a.fi--;a.se--;}
template<class T1,class T2>void operator++(pair<T1,T2>&a,int){a.fi++;a.se++;}
template<class T>void operator--(vc<T>&a,int){for(T&x:a)x--;}
template<class T>void operator++(vc<T>&a,int){for(T&x:a)x++;}
template<class T>void operator+=(vc<T>&a,T b){for(T&x:a)x+=b;}
template<class T>void operator-=(vc<T>&a,T b){for(T&x:a)x-=b;}
template<class T>void operator*=(vc<T>&a,T b){for(T&x:a)x*=b;}
template<class T>void operator/=(vc<T>&a,T b){for(T&x:a)x/=b;}
template<class T>void operator+=(vc<T>&a,const vc<T>&b){a.insert(a.end(),rng(b));}
template<class T1,class T2>pair<T1,T2>operator+(const pair<T1,T2>&a,const pair<T1,T2>&b){return {a.fi+b.fi,a.se+b.se};}
template<class T1,class T2>pair<T1,T2>operator-(const pair<T1,T2>&a,const pair<T1,T2>&b){return {a.fi-b.fi,a.se-b.se};}
template<class T>pair<T,T>operator*(const pair<T,T>&a,T b){return {a.fi*b,a.se*b};}
template<class T1,class T2>bool mins(T1& x,const T2&y){if(y<x){x=y;return true;}else return false;}
template<class T1,class T2>bool maxs(T1& x,const T2&y){if(x<y){x=y;return true;}else return false;}
template<class T>T min(const vc<T>&a){return *min_element(rng(a));}
template<class T>T max(const vc<T>&a){return *max_element(rng(a));}
template<class Tx,class Ty>Tx dup(Tx x, Ty y){return (x+y-1)/y;}
template<class T>ll suma(const vc<T>&a){ll s=0;for(auto&&x:a)s+=x;return s;}
template<class T>ll suma(const vv<T>&a){ll s=0;for(auto&&x:a)s+=suma(x);return s;}
template<class T>void uni(T&a){sort(rng(a));a.erase(unique(rng(a)),a.end());}
template<class T>void prepend(vc<T>&a,const T&x){a.insert(a.begin(),x);}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return;}
#define yes { puts("Yes"); return;}
#define no { puts("No"); return;}
#define rtn(x) { cout<<(x)<<'\n'; return;} // flush!
#define yn {puts("Yes");}else{puts("No");}

// Mod int
/*
const uint mod = 1000000007;/*/
const uint mod = 998244353;//*/
constexpr uint md(ll x) { x%=mod; return x<0?x+mod:x;}
constexpr ll md(ll x, ll m) { x%=m; return x<0?x+m:x;}
struct mint {
  uint x;
  mint(): x(0) {}
  mint(ll x):x(md(x)) {}
  mint operator-() const { return mint(0) - *this;}
  mint operator~() const { return mint(1) / *this;}
  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=(ull)x*a.x%mod; return *this;}
  mint& operator/=(const mint& a) { x=(ull)x*a.pow(mod-2).x%mod; return *this;}
  mint operator+(const mint& a) const { return mint(*this) += a;}
  mint operator-(const mint& a) const { return mint(*this) -= a;}
  mint operator*(const mint& a) const { return mint(*this) *= a;}
  mint operator/(const mint& a) const { return mint(*this) /= a;}
  mint pow(ll t) const {
    mint res = 1; for (mint p=x;t;p*=p,t>>=1) if (t&1) res *= p; return res;
  }
  mint ppow(ll t) const { int p=mod-1; return pow((t%p+p)%p);}
  bool operator<(const mint& a) const { return x < a.x;}
  bool operator==(const mint& a) const { return x == a.x;}
  bool operator!=(const mint& a) const { return x != a.x;}
};
mint ex(mint x, ll t) { return x.pow(t);}
istream& operator>>(istream&i,mint&a) {i>>a.x;return i;}
//*
ostream& operator<<(ostream&o,const mint&a) {o<<a.x;return o;}
/*/
ostream& operator<<(ostream&o, const mint&x) {
  int a = x.x, b = 1;
  rep(s,2)rep1(i,1000) {
    int y = ((s?-x:x)*i).x; if (abs(a)+b > y+i) a = s?-y:y, b = i;
  }
  o<<a; if (b != 1) o<<'/'<<b; return o;
}//*/
using vm = vector<mint>;
using vvm = vector<vm>;
struct modinv {
  int n; vm d;
  modinv(): n(2), d({0,1}) {}
  mint operator()(int i) { while (n <= i) d.pb(-d[mod%n]*(mod/n)), ++n; return d[i];}
  mint operator[](int i) const { return d[i];}
} invs;
struct modfact {
  int n; vm d;
  modfact(): n(2), d({1,1}) {}
  mint operator()(int i) { while (n <= i) d.pb(d.back()*n), ++n; return d[i];}
  mint operator[](int i) const { return d[i];}
} facs;
struct modfactinv {
  int n; vm d;
  modfactinv(): n(2), d({1,1}) {}
  mint operator()(int i) { while (n <= i) d.pb(d.back()*invs(n)), ++n; return d[i];}
  mint operator[](int i) const { return d[i];}
} ifacs;
mint comb(int a, int b) {
  if (a < b || b < 0) return 0;
  return facs(a)*ifacs(b)*ifacs(a-b);
}
struct modpow {
  mint x; int n; vm d;
  modpow(mint x=2): x(x), n(1), d(1,1) {}
  mint operator()(int i) { while (n <= i) d.pb(d.back()*x), ++n; return d[i];}
  mint operator[](int i) const { return d[i];}
} two(2);//, owt(invs(2));
//

// Fraction
struct frac {
  ll a, b;
  frac(ll _a=0, ll _b=1): a(_a), b(_b) {
    if (b == 0) a = 1; else if (b < 0) a = -a, b = -b;
    ll g = gcd(abs(a),b);
    a /= g; b /= g;
  }
  frac inv() const { return frac(b,a);}
  frac operator+(const frac& x) const { return frac(a*x.b + x.a*b, b*x.b);}
  frac operator-(const frac& x) const { return frac(a*x.b - x.a*b, b*x.b);}
  frac operator*(const frac& x) const { return frac(a*x.a, b*x.b);}
  frac operator/(const frac& x) const { return frac(a*x.b, b*x.a);}
  frac& operator+=(const frac& x) { return *this = *this + x;}
  frac& operator-=(const frac& x) { return *this = *this - x;}
  frac& operator*=(const frac& x) { return *this = *this * x;}
  frac& operator/=(const frac& x) { return *this = *this / x;}
  bool operator<(const frac& x) const { return a*x.b < x.a*b;}
  bool operator==(const frac& x) const { return a == x.a && b == x.b;}
  bool operator!=(const frac& x) const { return a != x.a || b != x.b;}
};
istream& operator>>(istream&i,frac&a){i>>a.a>>a.b;return i;}
ostream& operator<<(ostream&o,const frac&a){o<<a.a<<"/"<<a.b;return o;}
//
// coordinate compression
template<typename T=int>
struct X {
  bool ini; vc<T> d;
  X(): ini(false) {}
  /*
  X(vc<T>& a): ini(true), d(a) {
    init();
    for (T& na : a) na = (*this)(na);
  }// int only */
  void add(const T& x) { assert(!ini); d.pb(x);}
  void init() {
    sort(rng(d));
    d.erase(unique(rng(d)), d.end());
    ini = true;
  }
  int size() { if (!ini) init(); return sz(d);}
  T operator[](int i) { if (!ini) init(); return d[i];}
  int operator()(const T& x) {
    if (!ini) init();
    return upper_bound(rng(d),x)-d.begin()-1;
  }
  bool in(const T& x) { if (!ini) init(); return binary_search(rng(d),x);}
};
//

struct Solver {
  void solve() {
    int n, m;
    cin>>n>>m;
    vp ps(m);
    cin>>ps;
    X xs;
    for (auto& [l,r] : ps) xs.add(l), r++, xs.add(r);
    for (auto& [l,r] : ps) l = xs(l), r = xs(r);
    n = sz(xs);
    vi sr(n+1,INF), tr(n+1,-INF);
    {
      for (auto& [l,r] : ps) mins(sr[l], r);
      drep(i,n) mins(sr[i],sr[i+1]);
    }
    {
      for (auto& [l,r] : ps) maxs(tr[l], r);
      rep(i,n) maxs(tr[i+1], tr[i]);
    }

    frac ansr(1,1);
    for (auto [l,r] : ps) {
      int ai = l, bi = l;
      int a = 0, b = 0;
      while (1) {
        if (tr[ai] <= ai) break;
        ai = tr[ai]; a++;
        while (1) {
          if (sr[bi] > ai) break;
          bi = sr[bi]; b++;
        }
        frac now(b,a);
        if (ansr < now) ansr = now;
      }
    }
    mint ans = mint(ansr.a)/ansr.b;
    cout<<ans.x<<endl;
  }
};

int main() {
  // cin.tie(nullptr); ios::sync_with_stdio(false);
  int ts = 1;
  scanf("%d",&ts);
  rep1(ti,ts) {
    Solver solver;
    solver.solve();
  }
  return 0;
}