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

struct data
{
    int xx,yy;
}points[15];

int main ()
{
    int n,x,y; cin>>n;
    for(int i = 0; i<n; i++)
    {
        cin>>x>>y;
        points[i].xx = x; points[i].yy = y;
    }
    bool ok = true;
    for(int i = 1; i<n; i++)
    {
        if(points[i].xx != points[i-1].xx)
        {
            ok = false; break;
        }
    }
    bool ok1 = true;
    for(int i = 1; i<n; i++)
    {
        if(points[i].yy != points[i-1].yy)
        {
            ok1 = false; break;
        }
    }
    if(!ok && !ok1) cout<<"NO";
    else cout<<"YES"; return 0;
}