#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> vx(n,0);
    vector<int> vy(n,0);
    for(int a0 = 0; a0 < n; a0++){
        cin >> vx[a0] >> vy[a0];
    }
    sort(vx.begin(),vx.end());
    sort(vy.begin(),vy.end());
    
    if(vx[0]==vx[n-1] || vy[0] == vy[n-1])
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    return 0;
}