#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <set>
#include <algorithm>
using namespace std;


int main() {
    int n;
    cin>>n;
    int f=1;
    set<int>xs;
    set<int>ys;
    while(n--){
        int x,y;
        cin>>x>>y;
        xs.insert(x);
        ys.insert(y);
    }
    if(xs.size()>1 && ys.size()>1){
        cout<<"NO\n";
    }
    else{
        cout<<"YES\n";
    }
    return 0;
}