#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;


int main(){
    
    ll t;
    cin >> t;

    while(t){
        t--;

        ll n;
        cin >> n;

        ll cit = 0;
        ll menex = 0;

        vector<int> diagonal_occurences;

        for(int i = 0; i < n; i++){
            ll a,b;
            cin >> a >> b;

            ll diagonal = a+b;
            diagonal_occurences.push_back(diagonal);
        }

        sort(diagonal_occurences.begin(),diagonal_occurences.end());

        ll at = 0;
        ll current_diag = 0;
        ll current_diag_processed = 0;

        ll cit_good = 0;
        ll cit_bad = 0;

        ll men = 1;

        while(at < diagonal_occurences.size()){
            ll diag = diagonal_occurences[at];
            while(diag > current_diag){
                cit_good += (current_diag+1-current_diag_processed);
                current_diag_processed = 0;
                current_diag++;
                cit_good *= 2;
                cit_bad *= 2;
                men *= 2;
            }

            if(cit_good >= men){
                break;
            }

            current_diag_processed++;
            cit_bad++;

            if(cit_bad/men >= 3){
                break;
            }

            at++;
        }

        if(cit_bad/men >= 3){
            cout << "NO" << endl;
        }else{
            cout << "YES" << endl;
        }

        


    }


}