import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        ConsoleIO io = new ConsoleIO();
        new Main(io).solve();
        io.close();
    }
    ConsoleIO io;
    Main(ConsoleIO io) {
        this.io = io;
    }

    long MOD = 1_000_000_007;
    int N, M, K, Q;

    ArrayList<ArrayList<Integer>> gr;
    boolean[] visit;

    int[] st;
    int[] count;
    int[] cost;

    public void solve() {
        int inf = 1000000;
        int tests = io.ri();
        for(int test = 0;test<tests;test++){
            int n = io.ri();
            int[] xs = new int[n];
            int[] ys = new int[n];
            for(int i = 0;i<n;i++){
                int x = io.ri();
                int y = io.ri();
                xs[i] = x;
                ys[i] = y;
            }
            if(n < 3){
                io.writeLine("YES");
                continue;
            }
            boolean NO = true;
            for(int m = 0;m<(1<<n);m++) {
                int x1 = inf, x2 = inf, y1 = inf, y2 = inf;
                boolean bad = false;
                for (int i = 0; i < n; i++) {
                    if ((m & (1 << i)) > 0) {
                        if (x1 == xs[i] || x2 == xs[i]) continue;
                        if (x1 == inf) {
                            x1 = xs[i];
                        } else if (x2 == inf) {
                            x2 = xs[i];
                        } else {
                            bad = true;
                            break;
                        }
                    } else {
                        if (y1 == ys[i] || y2 == ys[i]) continue;
                        if (y1 == inf) {
                            y1 = ys[i];
                        } else if (y2 == inf) {
                            y2 = ys[i];
                        } else {
                            bad = true;
                            break;
                        }
                    }
                }
                if (bad || x1 == inf || y1 == inf)
                    continue;
                int t = Math.min(x1, x2);
                x2 = Math.max(x1, x2);
                x1 = t;
                t = Math.min(y1, y2);
                y2 = Math.max(y1, y2);
                y1 = t;
                boolean good = false;
                if (x2 == inf && y2 == inf) {
                    good = check(m, xs, ys, x1, inf, y1, inf);
                    good |= check(m, xs, ys, -inf, x1, y1, inf);
                    good |= check(m, xs, ys, x1, inf, -inf, y1);
                    good |= check(m, xs, ys, -inf, x1, -inf, y1);
                } else if (x2 == inf) {
                    good = check(m, xs, ys, x1, inf, y1, y2);
                    good |= check(m, xs, ys, -inf, x1, y1, y2);
                } else if (y2 == inf) {
                    good = check(m, xs, ys, x1, x2, y1, inf);
                    good |= check(m, xs, ys, x1, x2, -inf, y1);
                } else {
                    good = check(m, xs, ys, x1, x2, y1, y2);
                }
                if (good) {
                    io.writeLine("YES");
                    NO = false;
                    break;
                }
            }

            if(NO)
                io.writeLine("NO");
        }
    }

    boolean check(int m, int[] xs, int[] ys, int x1, int x2, int y1, int y2){
        for(int i = 0;i<xs.length;i++) {
            if ((m & (1 << i)) > 0) {
                if (ys[i] < y1 || ys[i] > y2) return false;
            } else {
                if (xs[i] < x1 || xs[i] > x2) return false;
            }
        }
        return true;
    }
}

class ConsoleIO {
    BufferedReader br;
    PrintWriter out;
    public ConsoleIO(){br = new BufferedReader(new InputStreamReader(System.in));out = new PrintWriter(System.out);}
    public void flush(){this.out.flush();}
    public void close(){this.out.close();}
    public void writeLine(String s) {this.out.println(s);}
    public void writeInt(int a) {this.out.print(a);this.out.print(' ');}
    public void writeWord(String s){
        this.out.print(s);
    }
    public void writeIntArray(int[] a, int k, String separator) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < k; i++) {
            if (i > 0) sb.append(separator);
            sb.append(a[i]);
        }
        this.writeLine(sb.toString());
    }
    public int read(char[] buf, int len){try {return br.read(buf,0,len);}catch (Exception ex){ return -1; }}
    public String readLine() {try {return br.readLine();}catch (Exception ex){ return "";}}
    public long[] readLongArray() {
        String[]n=this.readLine().trim().split("\\s+");long[]r=new long[n.length];
        for(int i=0;i<n.length;i++)r[i]=Long.parseLong(n[i]);
        return r;
    }
    public int[] readIntArray() {
        String[]n=this.readLine().trim().split("\\s+");int[]r=new int[n.length];
        for(int i=0;i<n.length;i++)r[i]=Integer.parseInt(n[i]);
        return r;
    }
    public int[] readIntArray(int n) {
        int[] res = new int[n];
        char[] all = this.readLine().toCharArray();
        int cur = 0;boolean have = false;
        int k = 0;
        boolean neg = false;
        for(int i = 0;i<all.length;i++){
            if(all[i]>='0' && all[i]<='9'){
                cur = cur*10+all[i]-'0';
                have = true;
            }else if(all[i]=='-') {
                neg = true;
            }
            else if(have){
                res[k++] = neg?-cur:cur;
                cur = 0;
                have = false;
                neg = false;
            }
        }
        if(have)res[k++] = neg?-cur:cur;
        return res;
    }
    public int ri() {
        try {
            int r = 0;
            boolean start = false;
            boolean neg = false;
            while (true) {
                int c = br.read();
                if (c >= '0' && c <= '9') {
                    r = r * 10 + c - '0';
                    start = true;
                } else if (!start && c == '-') {
                    start = true;
                    neg = true;
                } else if (start || c == -1) return neg ? -r : r;
            }
        } catch (Exception ex) {
            return -1;
        }
    }
    public long readLong() {
        try {
            long r = 0;
            boolean start = false;
            boolean neg = false;
            while (true) {
                int c = br.read();
                if (c >= '0' && c <= '9') {
                    r = r * 10 + c - '0';
                    start = true;
                } else if (!start && c == '-') {
                    start = true;
                    neg = true;
                } else if (start || c == -1) return neg ? -r : r;
            }
        } catch (Exception ex) {
            return -1;
        }
    }
    public String readWord() {
        try {
            boolean start = false;
            StringBuilder sb = new StringBuilder();
            while (true) {
                int c = br.read();
                if (c!= ' ' && c!= '\r' && c!='\n' && c!='\t') {
                    sb.append((char)c);
                    start = true;
                } else if (start || c == -1) return sb.toString();
            }
        } catch (Exception ex) {
            return "";
        }
    }
    public char readSymbol() {
        try {
            while (true) {
                int c = br.read();
                if (c != ' ' && c != '\r' && c != '\n' && c != '\t') {
                    return (char) c;
                }
            }
        } catch (Exception ex) {
            return 0;
        }
    }
    public char readChar(){try {return (char)br.read();}catch (Exception ex){ return 0; }}
}
class Pair {
    public Pair(int a, int b) {this.a = a;this.b = b;}
    public int a;
    public int b;
}
class Tri {
    public Tri(int a, int b, int c) {this.a = a;this.b = b;this.c = c;}
    public int a;
    public int b;
    public int c;
}
class PairLL {
    public PairLL(long a, long b) {this.a = a;this.b = b;}
    public long a;
    public long b;
}