#include<iostream>
#include<cstdlib>
#include<cstdio>
using namespace std;
int main()
{
  int n,i;
  //scanf("%d",&n);
    cin>>n;
  int *x,*y;
  x=(int *)malloc(n*sizeof(int));
  y=(int *)malloc(n*sizeof(int));
  for(i=0;i<n;i++)
  {
    //scanf("%d %d",&x[i],&y[i]);
      cin>>x[i]>>y[i];
  }
  int check_x=1,check_y=1;
  for(i=1;i<n;i++)
  {
    if(x[i]!=x[0])
    {
      check_x=0;
    }
    if(y[i]!=y[0])
    {
      check_y=0;
    }
  }
  if(check_x || check_y)
  {
    cout<<"YES"<<endl;
  }
  else
  {
    cout<<"NO"<<endl;
  }
}