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

public class Main implements Runnable {


    void solve() throws IOException {
        int n = nextInt();
        int[] a = new int[n];
        int[] b = new int[n];
        for (int i=0; i<n; i++) {
            a[i] = nextInt();
            b[i] = nextInt();
        }
        boolean xok = true, yok = true;
        for (int i=1; i<n; i++) {
            xok &= a[i]==a[0];
            yok &= b[i]==b[0];
        }
        if (xok || yok) {
            out.print("YES");
        } else {
            out.print("NO");
        }



    }

    BufferedReader br;
    StringTokenizer st;
    PrintWriter out;

    public void run() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);

            solve();
            br.close();
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(123);
        }
    }

    String next() throws IOException {
        while (st == null || !st.hasMoreTokens()) {
            String s = br.readLine();
            if (s == null)
                return null;
            st = new StringTokenizer(s);
        }
        return st.nextToken();
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    public static void main(String[] args) {
        new Thread(new Main()).start();
    }
}