#include <bits/stdc++.h>
using namespace std;
const int N = 51, V = 26 * 50000;
int n;
int a[N];
bitset<V> f[51][26];
vector<int> b1, b2;
int main() {
  scanf("%d", &n);
  int sum = 0;
  for (int i = 1; i <= (n << 1); i++) {
    scanf("%d", a + i);
    sum += a[i];
  }
  sort(a + 1, a + (n << 1) + 1);
  f[0][0].set(0);
  b1.push_back(a[1]);
  sum -= a[1], sum -= a[2];
  b2.push_back(a[2]);
  for (int i = 1; i <= n * 2 - 2; i++) a[i] = a[i + 2];
  for (int i = 1; i <= (n << 1) - 2; i++) {
    b2.push_back(a[i]);
    for (int j = min(n - 1, i); j; j--) {
      f[i][j] = f[i - 1][j] | (f[i - 1][j - 1] << a[i]);
    }
    f[i][0].set(0);
  }
  sum >>= 1;
  int pos = n * 2 - 2, cnt = n - 1;
  while (!f[pos][cnt].test(sum)) sum--;
  while (cnt) {
    if (a[pos] > sum || !f[pos - 1][cnt - 1].test(sum - a[pos])) {
      pos--;
    } else {
      cnt--;
      b2.erase(find(b2.begin(), b2.end(), a[pos]));
      b1.push_back(a[pos]);
      sum -= a[pos--];
    }
  }
  sort(b1.begin(), b1.end());
  sort(b2.begin(), b2.end(), greater<int>());
  for (auto x : b1) printf("%d ", x);
  putchar('\n');
  for (auto x : b2) printf("%d ", x);
  putchar('\n');
  return 0;
}
