#include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <set>
#include <map>
#include <vector>
#include <queue>
#include <string>
#include <iomanip>
#include <stdio.h>
#include <cstring>
#include <random>
#include <chrono>
#include <bitset>

using namespace std;
typedef long long ll;
typedef long double ld;

ll big = 1000000007ll;
float likeabutterfly;
string likeabee;
ll n,m,q,d,h,k,w,x;
ll T;

int main()
{
   ll c1,c3,c4,c5,c6;
    ll a,b,c,e,g;
    ll y,z;
    //freopen("stupd.txt","r",stdin);
    //freopen("output.txt","w",stdout);


    cin >> n;

    vector<ll> X;
    vector<ll> Y;

    for(c1 = 0; c1 < n; c1++){
        cin >> a >> b;
        X.push_back(a);
        Y.push_back(b);
    }

    ll yes = 1;
    ll yes2 = 1;

    for(c1 = 0; c1 < n-1; c1++){
        if(X[c1] != X[c1+1]){yes = 0;}
    }
    for(c1 = 0; c1 < n-1; c1++){
        if(Y[c1] != Y[c1+1]){yes2 = 0;}
    }

    if(yes == 1 || yes2 == 1){
        cout << "YES\n";

    }else{
    cout << "NO\n";}

	return 0;
}