#include<iostream>
#include<stdlib.h>

using namespace std;
struct points
{
    int x;
    int y;
};

int main()
{
    int n;
    cin>>n;
    int a,b;
    struct points point[n];
    for(int i=0;i<n;i++)
    {
        cin>>a>>b;
        point[i].x=a;
        point[i].y=b;
    }
    int xflag=0;
    int yflag=0;
    for(int i=1;i<n;i++)
    {
        if(point[0].x!=point[i].x)
            xflag=1;
        if(point[0].y!=point[i].y)
            yflag=1;
    }
    if(xflag==1&&yflag==1)
        cout<<"NO\n";
    else
        cout<<"YES\n";
    return 0;
}