#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=1000010;
int l[N];
int r[N];
int head[N];
int nexxt[N<<1];
int to[N<<1];
int cnt=1;
void ege(int a,int b)
{
    to[cnt]=b;
    nexxt[cnt]=head[a];
    head[a]=cnt++;
}
bool ok=true;
int vis[N];
void dfs(int s)
{
    for(int i=head[s];i;i=nexxt[i])
    {
        int nt=to[i];
        if(vis[nt])
        {
            ok=false;
            return;
        }
        vis[nt]=1;
        dfs(nt);
    }
}
void solve()
{
    int n;cin>>n;
    for(int i=1;i<=n;i++)
    cin>>l[i]>>r[i];
    fill(vis,vis+n+1,0);
    fill(head,head+n+1,0);
    cnt=1;ok=true;
    for(int i=1;i<=n;i++)
    {
        ege(l[i]-1,r[i]);
    }
    dfs(0);
    if(ok)cout<<1<<endl;
    else cout<<0<<endl;
}
signed main()
{
#ifdef ONLINE_JUDGE
#else
    freopen("in.in","r",stdin);
    freopen("out.out","w",stdout);
#endif
    ios::sync_with_stdio(false);cin.tie(0);
    int T;cin>>T;
    while(T--)
    {
        solve();
    }
}