#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],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]) cout<<"YES"<<endl;
   else if(y[0]==y[n-1]) cout<<"YES"<<endl;
       else cout<<"NO"<<endl;
    return 0;
}