#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];
    }
    bool flag = 1;
    if(x[1] != x[0] && y[1]!=y[0]){
        flag = 0;
    }
    else if(x[1] == x[0]){
        for(int i=2; i<n; i++){
            if(x[i] != x[0]){
                flag = 0;
                break;
            }
        }
    }
    else if(y[1] == y[0]){
        for(int i=2; i<n; i++){
            if(y[i] != y[0]){
                flag = 0;
                break;
            }
        }
    }
    if(flag == 0)
        cout<<"NO"<<endl;
    else
        cout<<"YES"<<endl;
    return 0;
}