#include <bits/stdc++.h>

#define endl '\n'
#define ll long long
using namespace std;

void solve(){
    ll n;
    cin>>n;
    vector<vector<ll>> e(n+1);
    for(ll i=0;i<n;i++){
        ll l,r;
        cin>>l>>r;
        e[l-1].emplace_back(r);
    }
    vector<bool> vis(n+1,false);
    for(ll i=0;i<=n;i++){
        if(!vis[i]){
            queue<ll> q;
            q.emplace(i);
            vis[i]=true;
            while(!q.empty()){
                ll u=q.front();
                q.pop();
                for(auto v:e[u]){
                    if(!vis[v]){
                        vis[v]=true;
                        q.emplace(v);
                    }
                    else{
                        cout<<0<<endl;
                        return;
                    }
                }
            }
        }
        vis.assign(n+1,false);
    }
    cout<<1<<endl;
}
int main() {
    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    ll t;
    cin>>t;
    while(t--)
        solve();
    return 0;
}