#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, xa, ya;
    cin >> n;
    bool sameX = true, sameY = true;
    cin >> xa >> ya;
    for(int a0 = 1; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        if (x != xa) {
            sameX = false;
        }
        if (y != ya) {
            sameY = false;
        }
    }
    if (sameX || sameY) cout << "YES" << endl;
    else cout << "NO" << endl;
    return 0;
}