#include <bits/stdc++.h>
using namespace std;
#define MOD 1000000007
#define pii pair<int, int>
#define pll pair<long long, long long>
#define vi  vector<int>
#define pb  push_back
#define mp  make_pair
#define ALL(x) x.begin(),x.end()
#define M(a,x) memset(a,x,sizeof(a))
#define sci(x) scanf("%d",&x);
#define scl(x) scanf("%lld",&x);
#define scs(x) scanf("%s",x);
#define print(x) printf("%d",x);
#define nl printf("\n")
#define fr first
#define se second
#define printl(x) printf("%lld",x)
#define F(i,a,n) for(int i=a;i<n;i++)
#define INF 100000000000000000LL
#define LL long long

const int N = 1e5+5;

int main() {
	int n;
	cin >> n;
	set<int> sx,sy;
	F(i,0,n){
		int x,y;
		sci(x);sci(y);
		sx.insert(x);
		sy.insert(y);
	}
	if(sx.size() == 1){
		cout<<"YES"<<endl;
		return 0;
	}
	else if(sy.size()==1){
		cout<<"YES"<<endl;
		return 0;
		
	}
	cout<<"NO"<<endl;
	return 0;
}