#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];
    int Y[n];
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> X[a0] >> Y[a0];
    }
    if(*min_element(X,X+n)==*max_element(X,X+n)||*min_element(Y,Y+n)==*max_element(Y,Y+n)) cout << "YES" << endl;
    else cout <<"NO" << endl;
    return 0;
}