#include <bits/stdc++.h>
using namespace std;
struct lenka {
  int t, in;
} a[1000000];
int cmp(const lenka& x, const lenka& y) {
  if (x.t == y.t) return x.in > y.in;
  return x.t < y.t;
}
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &a[2 * i].t, &a[2 * i + 1].t);
    a[2 * i].in = 1;
    a[2 * i + 1].in = -1;
  }
  sort(a, a + 2 * n, cmp);
  int ans = 0, in = 0;
  for (int i = 0; i < 2 * n; i++) {
    in += a[i].in;
    ans = max(ans, in);
  }
  puts(ans > 2 ? "NO" : "YES");
  return 0;
}
