import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

/**
 * Created by Tim Kilian on 20-06-2016.
 */

public class PointsOnALine {
    public InputStream in;
    public PrintWriter out;
    public Scanner sc;
    private String customIN = "";

    private void solution() {
        int n = readInt();
        int x = readInt();
        int y = readInt();
        boolean xt = true;
        boolean yt = true;
        for (int i = 1; i < n; i++) {
            int xi = readInt();
            int yi = readInt();
            if (x!=xi) xt = false;
            if (y!=yi) yt = false;
            if (xt==false && yt==false) break;
        }
        
        out.printf("%s", (xt||yt)? "YES" : "NO");
    }

    public void solve() {
        int T = 1;
//        T = readInt();
        while (T-- > 0)
            solution();
    }

    private void run() {
        in = customIN.isEmpty() ? System.in : new ByteArrayInputStream(customIN.getBytes());
        out = new PrintWriter(System.out);
        sc = new Scanner(in);
        long time = System.currentTimeMillis();

        solve();

        out.flush();
        if (!customIN.isEmpty()) printOut(System.currentTimeMillis() - time + " ms");
        exit();
    }

    public static void main(String[] args) {
        new PointsOnALine().run();
    }

    private int readInt() {
        return sc.nextInt();
    }

    private int[] readInt(int n) {
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) arr[i] = readInt();
        return arr;
    }

    private long readLong() {
        return sc.nextLong();
    }

    private long[] readLong(int n) {
        long[] arr = new long[n];
        for (int i = 0; i < n; i++) arr[i] = readLong();
        return arr;
    }

    private String readString() {
        return sc.next();
    }

    private double readDouble() {
        return Double.parseDouble(readString());
    }

    private static void printOut(Object... o) {
        System.out.println(Arrays.deepToString(o));
    }

    public void exit() {
        out.close();
        System.exit(0);
    }
}