#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int main(){
    int n;
    cin >> n;
    vector<std::pair<int, int>> v(n);
    for (int k = 0; k < n; k++) {
        cin >> v[k].first;
        cin >> v[k].second;
    }
    
    bool is_x = true;
    bool is_y = true;
    int x_0 = v[0].first;
    int y_0 = v[0].second;
    
    for (int i = 1; i < n; i++) {
        if (x_0 != v[i].first)
            is_x = false;
        
        if (y_0 != v[i].second)
            is_y = false;
        
        if (!is_x && !is_y) {
            std::cout << "NO" << std::endl;
            return 0;
        }
    }
    
    std::cout << "YES" << std::endl;
    
    return 0;
}