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

#define ll long long 
#define INF 0x3f3f3f3f
#define LNF 0x3f3f3f3f3f3f3f3fll
#define MOD 998244353

#define pii pair<int, int>

#define N 1000020

vector<int> G[N<<1], rG[N<<1], rngs[N];
int clr[N<<1];

int outdeg(int u) {
    return G[u].size();
}

void add_edge(int u, int v) {
    G[u].emplace_back(v);
    rG[v].emplace_back(u);
}

void walk(int u, int c) {
    clr[u] = c;
    for (auto v : rG[u]) {
        walk(v, c);
    }
}

int main() {
#ifdef TEST
    freopen("zz.in", "r+", stdin);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t; cin >> t;
    while (t --) {
        int n; cin >> n;

        for (int i = 0; i <= 2*n+10; ++ i) {
            G[i].clear(), rG[i].clear();
        }
        for (int i = 0; i <= n; ++ i) {
            rngs[i].clear();
            clr[i] = 0;
        }

        for (int i = 0; i < n; ++ i) {
            int l, r; cin >> l >> r;
            rngs[l].emplace_back(i);
            add_edge(i, r+1+n);
            add_edge(l+n, r+1+n);
        }

        for (int i = n+1; i <= 2*n+10; ++ i) {
            if (outdeg(i)) continue;
            walk(i, i);
        }   

        int res = 1;
        for (int i = 1; i <= n; ++ i) {
            unordered_map<int, int> cnt;
            for (auto x : rngs[i]) {
                assert(clr[x] != 0);
                if (++ cnt[clr[x]] >= 2) {
                    res = 0;
                }
            }
        }
        cout << res << '\n';
    }
}