#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,xp=0,yp=0,a,b;
    cin >> n;
    cin >> a >> b;
    for(int a0 = 0; a0 < n-1; a0++){
        int x;
        int y;
        cin >> x >> y;
        if(x-a == 0)
            {
            xp++;
        }
        if(y-b == 0)
            {
            yp++;
        }
        a= x;
        b = y;
        
    }
    if(xp == n-1 || yp == n-1) 
        {
        cout << "YES";
    }
    else
        {
        cout << "NO";
    }
    return 0;
}