#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin >> n;
    int x[n],y[n];
    for(int a0 = 0; a0 < n; a0++)
        cin >> x[a0] >> y[a0];
    bool xhas = true,yhas = true;
    for (int i=0;i<n;i++)
    {
        if (x[i] != x[0])
            xhas = false;
        if (y[i] != y[0])
            yhas = false;
    }
    if (xhas || yhas)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    
    return 0;
}