#include <iostream>
#include <fstream>
#include <iomanip>
#include <math.h>
#include <limits.h>
#include <algorithm>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <bitset>
#include <string>
#include <string.h>
#include <sstream>
#include <ctime>

using namespace std;

#define eps 1e-12
#define pi 3.14159265358979323846
#define pb push_back
#define mp make_pair

typedef pair<int,int> ii;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;



bool v,h;
int n,x[15],y[15];



int main()
{
	std::ios::sync_with_stdio(0);
	cin.tie(0);
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>x[i]>>y[i];
	}
	v=1;
	for(int i=2;i<=n;i++)
	{
		if(x[i]!=x[i-1])v=0;
	}
	h=1;
	for(int i=2;i<=n;i++)
	{
		if(y[i]!=y[i-1])h=0;
	}
	if(h||v)cout<<"YES\n";
	else cout<<"NO\n";
	return 0;
}