import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        new Solution().solve();
    }


    public void solve() {
        InputParser in = new InputParser(System.in);

        int n = in.readInt();

        int[] x = new int[n];
        int[] y = new int[n];
        
        for (int i = 0; i < n; i++) {
            x[i] = in.readInt();
            y[i] = in.readInt();
        }
        
        boolean done = true;
        
        for (int i = 1; i < n; i++) {
            if (x[i-1] != x[i]) {
                done = false;
                break;
            }
        }
        
        if (!done) {
            done = true;

            for (int i = 1; i < n; i++) {
                if (y[i-1] != y[i]) {
                    done = false;
                    break;
                }
            }
        }
        
        if (done) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }

    private int linearSearch(int[] a, int key) {
        for (int i = 0; i < a.length; i++) {
            if (a[i] == key)
                return i;
        }
        return -1;
    }

    private void printInLine(int[] a, String separator) {
        for (int i = 0; i < a.length; i++) {
            System.out.print(a[i]);
            if (i < a.length - 1)
                System.out.print(separator);
        }
    }

    private class InputParser {
        private final InputStream inputStream;
        private byte lastByte = -1;

        public InputParser(InputStream inputStream) {
            if (inputStream instanceof BufferedInputStream)
                this.inputStream = inputStream;
            else
                this.inputStream = new BufferedInputStream(inputStream);
        }

        public int readInt() {
            return (int) readLong();
        }

        public int[] readIntArray(int n) {
            int[] result = new int[n];

            for (int i = 0; i < n; i++) {
                result[i] = readInt();
            }

            return result;
        }

        public long readLong() {
            boolean negative = false;
            long result = 0;

            while ((lastByte < '0' || lastByte > '9') && lastByte != '-')
                readRawByte();

            if (lastByte == '-') {
                negative = true;
                readRawByte();
            }

            do {
                result *= 10;
                result += lastByte - '0';
                readRawByte();
            } while (lastByte >= '0' && lastByte <= '9');

            if (negative)
                return -result;
            else
                return result;
        }

        public long readBinaryLong() {
            boolean negative = false;
            long result = 0;

            while (lastByte != '0' && lastByte != '1' && lastByte != '-')
                readRawByte();

            if (lastByte == '-') {
                negative = true;
                readRawByte();
            }

            do {
                result *= 2;
                if (lastByte == '1')
                    result += 1;

                readRawByte();
            } while (lastByte == '0' || lastByte == '1');

            if (negative)
                return -result;
            else
                return result;
        }

        public long[] readLongArray(int n) {
            long[] result = new long[n];

            for (int i = 0; i < n; i++) {
                result[i] = readLong();
            }

            return result;
        }

        public void readRawByte() {
            try {
                lastByte = (byte) inputStream.read();
            } catch (IOException e) {
                lastByte = -1;
            }
        }

        public String readShortString() {
            String s = "";

            while (lastByte < 33 || lastByte > 126)
                readRawByte();

            while (lastByte >= 33 && lastByte <= 126) {
                s += (char) lastByte;
                readRawByte();
            }

            return s;
        }

        public String readString() {
            List<CharBuffer> buffers = new ArrayList<>();
            CharBuffer currentBuffer = new CharBuffer();

            while (lastByte < 33 || lastByte > 126)
                readRawByte();

            while (lastByte >= 33 && lastByte <= 126) {
                currentBuffer.add((char) lastByte);

                if (currentBuffer.isFull()) {
                    buffers.add(currentBuffer);
                    currentBuffer = new CharBuffer();
                }
                readRawByte();
            }

            char[] result = new char[buffers.size() * CharBuffer.CAPACITY + currentBuffer.currentSize];
            int i = 0;

            for (CharBuffer buffer : buffers) {
                for (int j = 0; j < CharBuffer.CAPACITY; j++) {
                    result[i++] = buffer.buffer[j];
                }
            }

            for (int j = 0; j < currentBuffer.currentSize; j++) {
                result[i++] = currentBuffer.buffer[j];
            }

            return String.valueOf(result);
        }

        public String readLine() {
            List<CharBuffer> buffers = new ArrayList<>();
            CharBuffer currentBuffer = new CharBuffer();

            while (lastByte == 10 || lastByte == 13 || lastByte == -1)
                readRawByte();

            while (lastByte != 10 && lastByte != 13 && lastByte != -1) {
                currentBuffer.add((char) lastByte);

                if (currentBuffer.isFull()) {
                    buffers.add(currentBuffer);
                    currentBuffer = new CharBuffer();
                }
                readRawByte();
            }

            char[] result = new char[buffers.size() * CharBuffer.CAPACITY + currentBuffer.currentSize];
            int i = 0;

            for (CharBuffer buffer : buffers) {
                for (int j = 0; j < CharBuffer.CAPACITY; j++) {
                    result[i++] = buffer.buffer[j];
                }
            }

            for (int j = 0; j < currentBuffer.currentSize; j++) {
                result[i++] = currentBuffer.buffer[j];
            }

            return String.valueOf(result);
        }

        private class CharBuffer {
            public static final int CAPACITY = 64;

            public final char[] buffer = new char[CAPACITY];
            public int currentSize = 0;

            public void add(char b) {
                buffer[currentSize++] = b;
            }

            public boolean isFull() {
                return currentSize == CAPACITY;
            }
        }
    }
}