#include<cstdio>
#include<cstring>
#include<complex>
#include<algorithm>
using namespace std;

const int MAXN = 10;
const int oops = 1e5;

typedef pair<int,int> Point;
#define X first
#define Y second

Point points[MAXN + 5];
int n;

int main() {
//    freopen("commute.in","r",stdin);
    int c,c2;
    int tests;
    scanf("%d",&tests);
    while (tests--) {
        scanf("%d",&n);
        int minX = oops, maxX = -oops, minY = oops, maxY = -oops;
        for (c=0;c<n;c++) {
            scanf("%d%d",&points[c].X,&points[c].Y);
            minX = min(minX, points[c].X);
            minY = min(minY, points[c].Y);
            maxX = max(maxX, points[c].X);
            maxY = max(maxY, points[c].Y);
        }
        bool yes = true;
        for (c=0;c<n;c++)
            yes &= points[c].X == minX || points[c].X == maxX || points[c].Y == minY || points[c].Y == maxY;
        printf("%s\n", yes ? "YES" : "NO");
    }
    return 0;
}