#include<queue>
#include<stack>
#include<string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <numeric>
#include <sstream>
#include<map>
#include<set>
#include<cstring>
#include <ctime>
#include<iostream>
#include<fstream>
#include<iomanip>
using namespace std;
#define sz     size()
#define pb push_back
#define mp make_pair
#define fo(i, n) for ( i = 1; i <= (int)(n); i++)
#define fr(i, k, n) for ( i = k; i <= (int)(n); i++)
#define sortvektor(s)   sort((s).begin(),(s).end())
#define reversevektor(s)   reverse((s).begin(),(s).end())
#define fro(i, n) for ( i = 0; i < (int)(n); i++)
#define meset(x,y) memset((x),(y),sizeof((x)))
long long stoll (string target) { stringstream s; s << target; long long w; s >> w; return w;}
int stoi (string target) { stringstream s; s << target; int w; s >> w; return w;}
string itos (int i) {stringstream s; s << i; return s.str();}
string lltos (long long i) {stringstream s; s << i; return s.str();}


int main()
{
ios::sync_with_stdio(false); // freopen("input.txt","r",stdin);  //freopen("output.txt","w",stdout);
bool ok=true,final=false;
int i,j,k,n,m; int t;
int br=0,odgovor=0,pom=0,mom=0,g=0,f=0,pamti=0;

// cin>>t; while(t--)


   int a[100001],b[100]; meset(a,0);
// cin>>t; while(t--)

    cin>>n; fo(i,n) cin>>a[i]>>b[i];
ok=true;
    fo(i,n)
    if (a[i]!=a[1]) ok=false;

    if (ok) {
    cout<<"YES"; return 0;}


    ok=true;
    fo(i,n)
    if (b[i]!=b[1])
    ok=false;
      if (ok) {
    cout<<"YES"; return 0;}
    cout<<"NO";
   return 0;
}