#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;
    vector <int>vx,vy;
    vector <int>::iterator it;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        vx.push_back(x);
        vy.push_back(y);
    }
    int x=0,y=0;
    for(int i=0;i<n-1;i++)
        {
        if(vx[i+1]==vx[i])
            x++;
        if(vy[i+1]==vy[i])
            y++;
    }
    if(x==n-1 || y==n-1)
        cout<<"YES";
    else
        cout<<"NO";
    return 0;
}