#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define endl '\n'
#define pii pair<int, int>
#define ar2 array<int, 2>
#define ar3 array<int, 3>
#define ve vector
#define vc vector<int>
#define pb push_back
#define pf push_front
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
// int dx[] = {-1, 0, 1, 0, -1, 1, 1, -1};
// int dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
const int llinf = 0x3f3f3f3f3f3f3f3f;
const int inf = 1e9;
const int N = 5e5 + 5;
int mod = 1e9 + 7;
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
int n, m, k;
void solve()
{
    cin >> n;
    vector<int> g[n + 1];
    vc in(n + 1);
    for (int i = 1; i <= n; i++)
    {
        int l, r;
        cin >> l >> r;
        g[l - 1].pb(r);
        in[r]++;
    }
    vc vis(n + 1);
    queue<int> q;
    q.push(0);
    while (!q.empty())
    {
        auto now = q.front();
        q.pop();
        if (vis[now])
        {
            cout << 0 << endl;
            return;
        }
        vis[now] = 1;
        for (auto it : g[now])
        {
            q.push(it);
        }
    }
    cout << 1 << endl;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int _ = 1;
    cin >> _;
    for (int i = 1; i <= _; i++)
    {
        solve();
    }
    return 0;
}