#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;
    int x[n], y[n];
    for(int i = 0; i < n; i++){
        cin >> x[i] >> y[i];
    }
    bool ans = true;
    for (int i = 1; i < n; i++) {
        if (x[i] != x[0]) {
            ans = false;
            break;
        }
    }
    if (!ans) {
        ans = true;
        for (int i = 1; i < n; i++) {
            if (y[i] != y[0]) {
                ans = false;
                break;
            }
        }
    }
    if (ans) cout << "YES\n";
    else cout << "NO\n";
    return 0;
}