#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef vector < int > VI;
typedef pair < int,int > II;
typedef vector < II > VII;
#define MOD 1000000007
#define EPS 1e-12
#define N 200100
#define PB push_back
#define MP make_pair
#define F first 
#define S second
#define ALL(v) v.begin(),v.end()
#define SZ(a) (int)a.size()
#define FILL(a,b) memset(a,b,sizeof(a))
#define SI(n) scanf("%d",&n)
#define SLL(n) scanf("%lld",&n)
#define PLLN(n) printf("%lld\n",n)
#define PIN(n) printf("%d\n",n)
#define REP(i,j,n) for(LL i=j;i<n;i++)
#define endl '\n'
#define TR1(x) cerr<<#x<<" : "<<x<<endl;
#define TR2(x,y) cerr<<#x<<" : "<<x<<" | "<<#y<<" : "<<y<<endl;
#define fast_io ios_base::sync_with_stdio(false);cin.tie(NULL)
int main() {
  int n; SI(n);
  int x[15] , y[15];
  REP(i,0,n) {
    SI(x[i]); SI(y[i]);
  }
  bool f1 = true , f2 = true;
  int xx = x[0] , yy = y[0];
  REP(i,0,n) {
    if(x[i] != xx) f1 = false;
    if(y[i] != yy) f2 = false;
  }
  if(f1 ||f2) printf("YES\n");
  else printf("NO\n");
  return 0;
}