#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 fx = -99, fy = -99;
    bool nox = false, noy = false;
    
    int n;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        
        if (fx == -99) {
            fx = x;
        } else {
            if (x != fx) nox = true;
        }
        if (fy == -99) {
            fy = y;
        } else {
            if (y != fy) noy = true;
        }
        
    }
    
    if (nox && noy) {
        cout << "NO" << endl;
    } else {
        cout << "YES" << endl;
    }
    
    return 0;
}