#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 * arr = new int [n];
    int * arr2 = new int [n];
    
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        arr[a0] = x;
        arr2[a0] = y;
    }
    bool flag = true;
    
    for ( int i = 0; i < n-1 && flag; i++) {
        if (  arr[i] == arr [i+1] || arr2[i] == arr2[i+1]) {
            flag = true;
        }
        else {
            flag = false;
        }
    }
    
    if ( flag) cout << "YES";
    else cout << "NO";
    return 0;
}