#pragma GCC optimize("Ofast", "inline", "unroll-loops")
#include <algorithm>
#include <chrono>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <queue>
#include <random>
#include <vector>
using namespace std;
#define rep(i, a, n) for (int i = a; i <= n; i++)
#define per(i, a, n) for (int i = a; i >= n; i--)
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define bit(x) (1ll << (x))
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
using VI = vector<int>;
using PII = pair<int, int>;
using ll = long long;
using ull = unsigned long long;
using db = double;
using ldb = long double;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// head

#ifdef DEBUG
#include "debug.cpp"
#else
#define debug(...) 42
#endif

const int N = 1e6 + 10;
int n;
struct line {
  std::vector<int> v;
  int sz;
  void add(int x) {
    v.push_back(x);
    sz++;
  }
  void del(int x) {
    v.push_back(-x);
    sz--;
  }
  void make() {
    std::sort(v.begin(), v.end(), [](int x, int y) {
      int a = std::abs(x), b = std::abs(y);
      return a != b ? a < b : x > y;
    });
    std::vector<int> w;
    for (auto &x : v) {
      if (x > 0) {
        w.push_back(x);
      } else {
        w.pop_back();
      }
    }
    v.swap(w);
  }
} lst[N], rst[N];
struct node {
  int sz, id;
  bool operator<(const node &o) const { return sz < o.sz; }
};
std::priority_queue<node> lp, rp;
void add(int l, int r) {
  lst[l].add(r);
  lp.push({lst[l].sz, l});
  rst[r].add(l);
  rp.push({rst[r].sz, r});
}
void del(int l, int r) {
  lst[l].del(r);
  lp.push({lst[l].sz, l});
  rst[r].del(l);
  rp.push({rst[r].sz, r});
}
int work() {
  while (true) {
    if (lp.top().sz >= rp.top().sz) {
      auto [sz, l] = lp.top();
      lp.pop();
      if (sz == 1) {
        return 1;
      }
      if (lst[l].sz != sz) {
        continue;
      }
      lst[l].make();
      auto tmp = lst[l].v;
      int pl = l;
      for (auto &r : tmp) {
        if (r < pl) {
          return 0;
        }
        del(l, r);
        add(pl, r);
        pl = r + 1;
      }
    } else {
      auto [sz, r] = rp.top();
      rp.pop();
      if (sz == 1) {
        return 1;
      }
      if (rst[r].sz != sz) {
        continue;
      }
      rst[r].make();
      auto tmp = rst[r].v;
      std::reverse(tmp.begin(), tmp.end());
      int pr = r;
      for (auto &l : tmp) {
        if (l > pr) {
          return 0;
        }
        del(l, r);
        add(l, pr);
        pr = l - 1;
      }
    }
  }
}
int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int t;
  cin >> t;
  while (t--) {
    // auto st = clock();
    cin >> n;
    // n = 1e6;
//    uniform_int_distribution<int> e(1, n);
    for (int i = 1; i <= n; i++) {
      lst[i].v.clear();
      lst[i].sz = 0;
      rst[i].v.clear();
      rst[i].sz = 0;
    }
    while (!lp.empty()) {
      lp.pop();
    }
    while (!rp.empty()) {
      rp.pop();
    }
    for (int i = 1; i <= n; i++) {
      int l, r;
      cin >> l >> r;
      // l = e(rng);
      // r = e(rng);
      // if (l > r) swap(l, r);
      add(l, r);
    }
    cout << work() << '\n';
    // auto ed = clock();
    // cout << "time: " << 1.0 * (ed - st) / CLOCKS_PER_SEC << '\n';
  }
  return 0;
}