#include<bits/stdc++.h>
using namespace std;
#define ll long long

int main()
{
    int n;
    cin>>n;
    map<int,int>one,two;
    while(n--)
    {
        int x,y;
        cin>>x>>y;
        one[x]++;
        two[y]++;
    }
    if(one.size()==1 || two.size()==1)
    cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}