#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second

const int N = 1e6;

int n;
pair<int, int> p[N];

set<array<int, 4>> s;
map<pair<int, int>, int> cnt_cell;

bool add(int x, int y, int cnt){
    if(cnt_cell[{x, y}]){
        s.erase({x + y, x, y, cnt_cell[{x, y}]});
    }
    cnt_cell[{x, y}] += cnt;
    s.insert({x + y, x, y, cnt_cell[{x, y}]});
    if(cnt_cell[{x, y}] >= 4){
        return false;
    }
    return true;
}

bool solve2(){
    s.clear();
    cnt_cell.clear();

    for(int i = 1; i <= n; ++i){
        cnt_cell[{p[i].first, p[i].second}]++;
    }
    cnt_cell[{0, 0}] += 1;

    for(auto [p, cnt_p]: cnt_cell){
        s.insert({p.first + p.second, p.first, p.second, cnt_p});
    }

    while(!s.empty()){
        auto [sum, x, y, cnt] = *s.begin();
        s.erase(s.begin());

        if(cnt >= 4){
            return false;
        }
        --cnt;
        
        if(!cnt) continue;

        if(!add(x + 1, y, cnt)){
            return false;
        }
        if(!add(y, x + 1, cnt)){
            return false;
        }
    }

    return true;
}

void solve(){
    cin >> n;
    map<int,int>mp;
    for(int i=1; i<=n ;i++){
        int x,y;cin >> x >> y;
        p[i] = {x, y};
        mp[-(x+y)]++;
    }
    while(!mp.empty()){
        auto it=mp.begin();
        if(it->fi>=0) break;
        if(it->se<=1){
            mp.erase(it);
            continue;
        }
        mp[it->fi+1]+=it->se/2;
        mp.erase(it);
    }
    if(mp[0]>=3){
        cout <<"NO\n";
        return;
    }
    
    if(solve2()){
        cout << "YES\n";
    }
    else{
        cout << "NO\n";
    }
}
int main(){
    ios::sync_with_stdio(false);cin.tie(0);
    int t;cin >> t;while(t--) solve();
}