#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define LL long long
#define st first
#define nd second
using namespace std;
int n,x,y,cntx[21],cnty[21];
int main(){
	cin>>n;
	for(int i=0;i<n;++i){
		cin>>x>>y;
		cntx[x+10]++;
		cnty[y+10]++;
	}
	for(int i=0;i<21;++i)
		if(cntx[i]==n||cnty[i]==n){
			puts("YES");
			return 0;
		}
	puts("NO");
}