#include <bits/stdc++.h>
#define MOD 1000000007
#define INF 1000000000
#define vi vector<int>
using namespace std;
int n;
vi x(11);
vi y(11);
int main()
{
	cin>>n;
	for(int i=0;i<n;i++)
		cin>>x[i]>>y[i];
	bool isx = true, isy = true;
	for(int i=0;i<n-1;i++)
	{
		if(x[i]!=x[i+1])
			isx = false;
		if(y[i]!=y[i+1])
			isy = false;
	}

	if(isx || isy)
		cout<<"YES";
	else
		cout<<"NO";
	return 0;
}