#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;
    
    vector<int> x_coord;
    vector<int> y_coord;
    
    // Retrieve coordinates
    for(int i = 0; i < n; i++){
        int x;
        int y;
        cin >> x >> y;
        x_coord.push_back(x);
        y_coord.push_back(y);
    }
    
    // Check if all ccordinates are on same horizontal or vertical line
    int x_count = 0;
    int y_count = 0;
    
    for (int i = 0; i < x_coord.size() - 1; i++){
        if (x_coord[i] == x_coord[i + 1]){
            x_count++;
        }
    }
    
    for (int i = 0; i < y_coord.size() - 1; i++){
        if (y_coord[i] == y_coord[i + 1]){
            y_count++;
        }
    }
    
    if (x_count == x_coord.size() - 1 || y_count == y_coord.size() - 1){
        cout << "YES" << "\n";
    }
    else{
        cout << "NO" << "\n";
    }
    
    return 0;
}