#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;
    
    pair<int, int> *p1;
    p1 = new pair<int, int> [n];
    
    for(int a0 = 0; a0 < n; a0++)
    {
        int x;
        int y;
        cin >> x >> y;
        p1[a0].first = x;
        p1[a0].second = y;
    }
    
    int count(0), count1(0);
    for(int a0 = 1; a0 < n; a0++)
    {
        
        if(p1[a0].first == p1[0].first)
        {
            count++;
        }
        
        if(p1[a0].second == p1[0].second)
        {
            count1++;
        }
    }
    
    if(count1 == n-1 || count == n-1)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    
    
  
    return 0;
}