#include <bits/stdc++.h>
using namespace std;
const int N = 1e6+7;
int n;
int l[N],r[N];
vector<int> g[N];
int ru[N];
void solve()
{
    cin>>n;
    for(int i=1;i<=n;i++) cin>>l[i]>>r[i];
    for(int i=1;i<=n + 1;i++) ru[i] = 0 , g[i].clear();
    for(int i=1;i<=n;i++) {
        g[l[i]].push_back(r[i] + 1);
        ru[r[i] + 1] ++;
    }

    for(int i=1;i<=n;i++)
    {
        if(ru[l[i]]) continue;
        queue<int> q;
        vector<int> siz(n+2);
        q.push(l[i]);
        while(!q.empty())
        {
            int x = q.front(); q.pop();
            siz[x] ++;
            if(siz[x] >= 2)
            {
                cout<<0<<"\n";
                return ;
            }
            for (auto y: g[x]) {
                q.push(y);
            }
        }
    }
    cout<<1<<"\n";
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    int T = 1;
    cin>>T;
    while(T--) solve();
    return 0;
}