#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
inline int GCD(int x, int y) {
  if (x < y) swap(x, y);
  if (x == 0) return y;
  if (y == 0) return x;
  return GCD(x % y, y);
}
int phi(int n) {
  int result = n;
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      while (n % i == 0) n /= i;
      result -= result / i;
    }
  }
  if (n > 1) result -= result / n;
  return result;
}
int power(int x, int n, int mod) {
  int res = 1;
  x %= mod;
  while (n) {
    if (n & 1) {
      res = ((res * x) % mod + mod) % mod;
    }
    x = ((x * x) % mod + mod) % mod;
    n >>= 1;
  }
  return res;
}
inline bool func(const pair<int, int> &a, const pair<int, int> &b) {
  if (a.second < b.second) return true;
  if (a.second == b.second) {
    if (a.first >= b.first) return true;
    return false;
  }
  return false;
}
const int MAXN = 6e3 + 5;
int dp[MAXN][MAXN];
int SIZ, N;
vector<int> Rs[MAXN];
void clear() {
  for (int i = 0; i <= SIZ; i++) {
    for (int j = 0; j <= SIZ; j++) dp[i][j] = -1;
    Rs[i].clear();
  }
}
int solve(int l, int r) {
  if (l > r) return 0;
  if (dp[l][r] != -1) return dp[l][r];
  int kitne = count(Rs[l].begin(), Rs[l].end(), r);
  dp[l][r] = max(dp[l][r], kitne + (l + 1 > r ? 0 : solve(l + 1, r)));
  for (int i = 0; i < Rs[l].size(); i++) {
    int R = Rs[l][i];
    if (R >= r) continue;
    dp[l][r] = max(dp[l][r], kitne + solve(l, R) + solve(R + 1, r));
  }
  return dp[l][r];
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  int test;
  cin >> test;
  while (test--) {
    cin >> N;
    vector<int> v;
    vector<int> L(N + 1), R(N + 1);
    for (int i = 1; i <= N; i++) {
      cin >> L[i] >> R[i];
      v.push_back(L[i]);
      v.push_back(R[i]);
    }
    sort(v.begin(), v.end());
    v.resize(unique(v.begin(), v.end()) - v.begin());
    for (int i = 1; i <= N; i++) {
      L[i] = lower_bound(v.begin(), v.end(), L[i]) - v.begin();
      R[i] = lower_bound(v.begin(), v.end(), R[i]) - v.begin();
    }
    SIZ = v.size() + 1;
    clear();
    for (int i = 1; i <= N; i++) {
      Rs[L[i]].push_back(R[i]);
    }
    int ans = solve(0, SIZ);
    cout << ans << endl;
  }
}
