import java.util.Scanner;

/*
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 */
/**
 *
 * @author iiitk101
 */
class points {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        int x[] = new int[t];
        int y[] = new int[t];
        String result = "YES";
        int flagX = 0, flagY = 0;
        for (int i = 0; i < t; i++) {
            x[i] = sc.nextInt();
            y[i] = sc.nextInt();
            if (x[i] == 0) {
                flagX = 1;
            }
        }
        if (flagX == 1) {
            for (int j = 1; j < t; j++) {
                if (x[j] != 0) {
                    result = "NO";
                }
            }
        } else if (flagY == 1) {
            for (int j = 1; j < t; j++) {
                if (y[j] != 0) {
                    result = "NO";
                }
            }
        } 
        System.out.println(result);
    }
}