#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N=1e6+10;
const ll INF=1e11+10;
struct EDGE{
	ll to,nxt;
}e[N<<1];
ll n,ans=0;
ll head[N],cnt,vis[N];
void add(ll u,ll v){
	e[++cnt].to=v;
	e[cnt].nxt=head[u];
	head[u]=cnt;
}
void dfs(ll now){
	vis[now]=1;
	for(ll i=head[now];i;i=e[i].nxt){
		ll v=e[i].to;
		if(vis[v])ans=0;
		else dfs(v);
	}
}
void solve(void){
	cin>>n;
	ll root=0;
	cnt=0;ans=1;
	for(ll i=1;i<=n+1;++i)head[i]=0;
	for(ll i=1;i<=n;++i){
		ll u,v;
		cin>>u>>v;
		add(u,v+1);
		if(i==1)root=u;
		vis[i]=0;
	}
	vis[n+1]=0;
	dfs(root);
	cout<<ans<<endl;


}
int main(void){
	ios::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);
	ll times=1;
	cin>>times;
	while(times--)solve();
	return 0;
}