#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T> void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T> void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 1000010;

int n, fa[maxn];

int find(int x) {
  return fa[x] == x ? x : fa[x] = find(fa[x]);
}

void work() {
  cin >> n;
  rep (i, 1, n) fa[i] = i;
  int ok = 0, loop = 0;
  rep (i, 1, n) {
    int x, y;
    cin >> x >> y;
    if (x == 1 && y == 1) {
      ok = 1;
    } else {
      x = max(1, x - 1);
      if (find(x) == find(y)) loop = 1;
      fa[find(x)] = find(y);
    }
  }
  cout << (ok && !loop) << '\n';
}

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  int t; cin >> t;
  while (t--) work();
}