#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;
    set <int> x;
    set <int> y;
    for (int i =0; i < n; i++)
    {
        int a,b;
        cin >> a >> b;
        x.insert(a);
        y.insert(b);
    }
    cout << (x.size() == 1 || y.size() == 1 ? "YES" : "NO") << endl;
    return 0;
}