#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 arr1[n],arr2[n];
    for(int a0 = 0; a0 < n; a0++){
        cin >> arr1[a0] >> arr2[a0];
    }
    sort(arr1,arr1+n);
    sort(arr2,arr2+n);
    if(arr1[0]==arr1[n-1]||arr2[0]==arr2[n-1])
        cout<<"YES";
    else
        cout<<"NO";
    return 0;
}