#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;

typedef pair<double, double> coordinate;

void f(vector<coordinate> A){
    int size = A.size();
    int x = A.at(0).first;
    int y = A.at(0).second;
    bool x_const = true;
    bool y_const = true;
    for (int i = 1; i < size; i++){
        if (A.at(i).first != A.at(i - 1).first){
            x_const = false;
        }
        if (A.at(i).second != A.at(i - 1).second){
            y_const = false;
        }
    }
    if (x_const || y_const){
        cout << "YES" << endl;
        return ;
    }
    cout << "NO" << endl;
}
int main(){
    int n;
    double x, y;
    cin >> n;
    vector<coordinate> arr;
    for(int a0 = 0; a0 < n; a0++){
        cin >> x >> y;
        arr.push_back(make_pair(x, y));
    }
    f(arr);
    return 0;
}