#include <iostream>
#include <iosfwd>
#include <iomanip>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <ctime>
#include <cmath>
#include <cassert>
#include <cctype>
#include <climits>
#include <vector>
#include <bitset>
#include <set>
#include <queue>
#include <stack>
#include <map>
#include <deque>
#include <string>
#include <list>
#include <iterator>
#include <sstream>
#include <complex>
#include <fstream>
#include <functional>
#include <numeric>
#include <utility>
#include <algorithm>
#include <assert.h>
#include <unordered_map>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef double ld;
typedef vector < long long > vll;
typedef pair <long long, long long> pll;
typedef pair <int, int> pii;
typedef vector < int > vii;
typedef complex < double > Point;

#define csl ios_base::sync_with_stdio(false); cin.tie(NULL)
#define mp make_pair
#define fst first
#define snd second

ll t, n, m, u, v, q, r, ql, qr, k, l, s, w, z, x, y, d, p, c, L, b;
const int N = 2e5 + 500;
const int NN = 1e4 + 4;
const long long mod = 1e9 + 7;
const long long INF = 1LL << 52LL;

int wx, wy, ex, ey, xx[N], yy[N];
bool in(int xa, int ya) {
    if (xa > ex || xa < wx) return false;
    if (ya > wy || ya < ey) return false;
    if (xa == wx || ya == wy || xa == ex || ya == ey) return true;
    return false;
    
}
int main() {
    csl;
    cin >> q;
    while (q--) {
        cin >> n;
        for (int i = 0; i < n; ++i) {
            cin >> xx[i] >> yy[i];
        }
        bool valid = false;
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < n; ++j) {
                for (int k = 0; k < n; ++k) {
                    for (int l = 0; l < n; ++l) {
                        wx = xx[i];
                        wy = yy[j];
                        ex = xx[k];
                        ey = yy[l];
                        if (wx == ex) wx = ex - 1;
                        if (wy == ey) wy = ey + 1;
                        if (wx > ex) swap(wx, ex);
                        if (ey > wy) swap(wy, ey);
                        if (wx >= ex || wy <= ey) continue;
                        bool Valid = true;
                        for (int m = 0; m < n; ++m) {
                            Valid &= in(xx[m], yy[m]);
                        }
                        valid |= Valid;
                    }
                }
            }
        }
        if (valid) cout << "YES\n";
        else cout << "NO\n";
    }
    return 0;
}