#include <bits/stdc++.h>

using namespace std;

int x[12345], y[12345];

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d %d", x + i, y + i);
  }
  bool okx = true, oky = true;
  for (int i = 0; i < n; i++) {
    if (x[i] != x[0]) okx = false;
    if (y[i] != y[0]) oky = false;
  }
  puts((okx || oky) ? "YES" : "NO");
  return 0;
}