#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	int x[n],y[n],count1=1,count2=1,count3=0;
	for(int i=0;i<n;++i)
	{
		cin>>x[i]>>y[i];
		if(x[i]==x[i-1]&&i!=0)
		++count1;
		if(y[i]==y[i-1]&&i!=0)
		++count2;
	}
	if(count1==n||count2==n)
	{
		cout<<"YES";
		return 0;
	}
    else 
        cout<<"NO";
	/*if(x[1]-x[0]!=0)
	{
		double m=(y[1]-y[0])/(x[1]-x[0]);
		for(int i=2;i<n;++i)
		{
			if(y[i]-y[0]==m*(x[i]-x[0]))
			++count3;
			else
			break;
		}
		if(count3==n-2)
		cout<<"YES";
		else
		cout<<"NO";
	}*/
	return 0;
}