#include <bits/stdc++.h>
using namespace std;
template <class T>
bool umin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool umax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
int arr[100009], ans[100009];
int main() {
  int a;
  scanf("%d", &a);
  for (int i = 1; i <= a; i++) scanf("%d", arr + i);
  sort(arr + 1, arr + a + 1);
  int st = 1, en = a;
  for (int i = 1; i <= a; i += 2) ans[i] = arr[st++];
  for (int i = 2; i <= a; i += 2) ans[i] = arr[en--];
  if (a & 1) ans[a + 1] = 2147483647;
  ans[0] = 2147483647;
  for (int i = 1; i <= a; i++) {
    if (i & 1) {
      if (ans[i] > ans[i + 1] or ans[i] > ans[i - 1]) {
        printf("Impossible\n");
        return 0;
      }
    } else {
      if (ans[i] < ans[i + 1] or ans[i] < ans[i - 1]) {
        printf("Impossible\n");
        return 0;
      }
    }
  }
  for (int i = 1; i <= a; i++) printf("%d ", ans[i]);
  printf("\n");
  return 0;
}
