#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

#define all(a) (a).begin(),(a).end()
#define pb push_back
#define sz(a) ((int)(a).size())
#define mp make_pair
#define fi first
#define se second

typedef pair<int,int> pint;
typedef long long ll;
typedef vector<int> vi;



int main()
{
	int n;
	scanf("%d",&n);
	int x,y;
	scanf("%d %d",&x,&y);
	bool sx=true,sy=true;
	for (n--; n; n--)
	{
		int xi,yi;
		scanf("%d %d",&xi,&yi);
		sx&=x==xi;
		sy&=y==yi;
	}
	if (sx||sy)
		printf("YES\n");
	else
		printf("NO\n");
	return 0;
}