#include "bits/stdc++.h"
using namespace std;

int id[1000010],sz[1000010];

int solve() {
    int n;
    scanf("%d",&n);
    for (int i=1;i<=n;i++) {
        id[i]=i;
        sz[i]=0;
    }
    vector<priority_queue<int,vector<int>,greater<int>>> a(n+1);
    for (int i=1;i<=n;i++) {
        int l,r;
        scanf("%d%d",&l,&r);
        a[l].push(r);
        sz[l]++;
    }    
    for (int i=1;i<=n;i++) {
        if (a[id[i]].empty() || a[id[i]].top() < i) return 0;
        int v = a[id[i]].top();
        a[id[i]].pop();
        if (sz[id[i]]>sz[id[v+1]]) swap(id[i],id[v+1]); 

        while (!a[id[i]].empty()) {
            a[id[v+1]].push(a[id[i]].top());
            a[id[i]].pop();
        }
        sz[id[v+1]]+=sz[id[i]]-1;
    }   
    return 1;
}


int main() {

    int T;
    scanf("%d",&T);
    while (T--) {
        printf("%d\n",solve());
    }

    return 0;
}