#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;
    bool a_line = true, b_line = true;
    int a = NULL, b = NULL;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
    
        if(a == NULL){
            a = x; b = y;
        }else {
            a_line = (a==x && a_line)? true : false;
            b_line = (b==y && b_line)? true : false;
        }
    }
    if(a_line || b_line)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    return 0;
}