#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i;
  cin >> n;
  int a[n + 1];
  for (i = 0; i < n; i++) {
    cin >> a[i];
  }
  sort(a, a + n);
  for (i = 0; i < n; i += 2) {
    cout << a[i] << " ";
  }
  for (i = n - 1; i >= 0; i--) {
    if (i % 2 != 0) cout << a[i] << " ";
  }
  cout << endl;
}
