#include <bits/stdc++.h>

#define REP(i, n)	for(int i=0;i<n;i++)
#define REPN(i, n)	for(int i=1;i<=n;i++)
#define SET(i, n)	memset(i, n, sizeof(i))

#define MAX 		100050
#define MOD			1000000007
#define INF			(1 << 29)
#define pb			push_back
#define EPS  		1e-6

using namespace std;

typedef long long ll;
typedef pair<int, int>	pii;

int main(){
	map<int, int>X, Y;
    int n;
    cin >> n;
    REP(i, n){
        int x, y;
        cin >> x >> y;
        X[x]++;
        Y[y]++;
    }
    if(X.size() == 1 || Y.size() == 1) cout << "YES\n";
    else cout << "NO\n";
	return 0;
}