#include <iostream>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <iterator>
#include <map>
#include <cstring>
#include <climits>
#include <time.h>

using namespace std;

#define READ() 	freopen("in.txt","r",stdin)
#define WRITE() freopen("out.txt","w",stdout)
#define sf(n) 	scanf("%d",&n)
#define lsf(n) 	scanf("%lld", &n)
#define pb(n) 	push_back(n)
#define EPS 	1e-10
#define NL 		printf("\n")
#define INF     INT_MAX
#define MAX     INT_MAX
#define MOD     1000000007
#define LL      long long

int main()
{
//    READ();
//    WRITE();

    int n;
    sf(n);
    LL x,y,xMain,yMain;

    bool foundX = true;
    bool foundY = true;

    lsf(xMain);
    lsf(yMain);

    for(int i=0;i<n-1;i++)
    {
        lsf(x);
        lsf(y);
        if(x != xMain)foundX = false;
        if(y != yMain)foundY = false;
    }

    if(foundX || foundY)cout << "YES" << endl;
    else cout << "NO" << endl;


    return 0;
}