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