#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll i,j,m,n,p,q,x,y;
map<ll,ll>mp,mp1;
int main()
{
    cin>>n;for(i=1;i<=n;i++)
    {
        cin>>x>>y;
        mp[x]++;mp1[y]++;
    }
    if((mp.size()==1||mp1.size()==1)&&(mp.size()!=mp1.size()))
        cout<<"YES\n";
    else
        cout<<"NO\n";
}