/*
    *
    * Cyrus Jackson
    * VIT University - India
    *
*/
#include <iostream>
#include <cassert>
#include <stdio.h>
#include <string>
#include <cstdlib>
#include <cmath>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <map>
#include <queue>
#include <stack>
#define test()    int test_case;cin>>test_case;while(test_case--)
#define forOne(i,n) for(int i = 1; i <= n; i++)
#define forN(i,n) for(int i = 0; i < n; i++)
#define forA(i,a,n) for(int i = a; i <= n; i++)
#define s(t) scanf("%d",&t)

using namespace std;
bool compare(const pair<int,pair<int,int> >&i, const pair<int,pair<int,int> >&j)
{
    return i.second.first < j.second.first;
}
typedef vector<pair<int,int> > m1;


int main(){
    int a[100][100];
    int n,flagX = 0,flagY = 0;
    cin>>n;
    forN(i,n)
    {
        cin>>a[i][0];
        cin>>a[i][1];
    }
    int x,y;
    x = a[0][0];
    y = a[0][1];
    forN(i,n)
    {
        if(a[i][0] != x)
        {
            flagX = 1;
            break;
        }
    }
    forN(i,n)
    {      
            if(a[i][1] != y)
            {
                flagY = 1;
                break;
            }
        
    }
    if(flagX == 1 && flagY == 1)
        cout<<"NO\n";
    else
        cout<<"YES\n";
    flagX = 0;

    return 0;
}