#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<pair<int, int>> dots;
    
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        dots.emplace_back(x, y);
    }
   
    auto const p0 = dots.front();
    
    if(all_of(dots.begin(), dots.end(), [p0](pair<int, int> const & p) { return p.first == p0.first; })
       || all_of(dots.begin(), dots.end(), [p0](pair<int, int> const & p) { return p.second == p0.second; }))
    {
        cout << "YES";
    }
    else
    {
        cout << "NO";
    }
    cout << endl;
    
    return 0;
}