#include <bits/stdc++.h>
bool DEBUG = false;
using namespace std;
int n, a[100000];
int main() {
  scanf("%d", &n);
  for (int i = 0; i < (n); ++i) scanf("%d", &a[i]);
  sort(a, a + n);
  int* pt = unique(a, a + n);
  n = pt - a;
  for (int i = (1); i < (n); ++i)
    if (a[i - 1] == 1)
      continue;
    else if (a[i] >= a[i - 1] + 1 && a[i] <= 2 * a[i - 1] - 1) {
      puts("YES");
      return 0;
    }
  puts("NO");
  return 0;
}
