#include <iostream>
#include <iomanip>
#include <fstream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <cmath>
#include <cstring>
#include <string>
#include <algorithm>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <complex>
#include <random>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;

int N;
set<int> X, Y;

int main()
{
    cin >> N;
    for (int i = 0, x, y; i < N; i++)
    {
        cin >> x >> y;
        X.insert(x);
        Y.insert(y);
    }

    if (X.size() == 1 || Y.size() == 1)
        cout << "YES\n";
    else
        cout << "NO\n";

    return 0;
}