#include <bits/stdc++.h>
struct MI {
 private:
  char bb[1 << 14];
  FILE* f;
  char *bs, *be;
  char e;
  bool o, l;

 public:
  MI() : f(stdin), bs(0), be(0) {}
  inline char get() {
    if (o) {
      o = 0;
      return e;
    }
    if (bs == be) be = (bs = bb) + fread(bb, 1, sizeof(bb), f);
    if (bs == be) {
      l = 1;
      return -1;
    };
    return *bs++;
  }
  inline void unget(char c) {
    o = 1;
    e = c;
  }
  template <class T>
  inline T read() {
    T r;
    *this > r;
    return r;
  }
  template <class T>
  inline MI& operator>(T&);
};
template <class T>
struct Q {
  const static bool U = T(-1) >= T(0);
  inline void operator()(MI& t, T& r) const {
    r = 0;
    char c;
    bool y = 0;
    if (U)
      for (;;) {
        c = t.get();
        if (c == -1) goto E;
        if (isdigit(c)) break;
      }
    else
      for (;;) {
        c = t.get();
        if (c == -1) goto E;
        if (c == '-') {
          c = t.get();
          if (isdigit(c)) {
            y = 1;
            break;
          };
        } else if (isdigit(c))
          break;
        ;
      };
    for (;;) {
      if (c == -1) goto E;
      if (isdigit(c))
        r = r * 10 + (c ^ 48);
      else
        break;
      c = t.get();
    }
    t.unget(c);
  E:;
    if (y) r = -r;
  }
};
template <>
struct Q<char> {};
template <class T>
inline MI& MI::operator>(T& t) {
  Q<T>()(*this, t);
  return *this;
}
template <class T>
std::ostream& operator<(std::ostream& out, const T& t) {
  return out << t;
}
using std::cout;
MI cin;
const int $n = 205;
const int $p = $n * 2;
int n, pt, deg[$p], fa[$p];
bool e[$n * 6];
struct group {
  bool who;
  int v[3];
  inline void init(bool who, int x) {
    this->who = who;
    v[0] = x;
    v[1] = v[2] = 0;
  }
  inline bool add(int x) {
    if (!v[0]) {
      v[0] = x;
      return 0;
    }
    if (!v[1]) {
      v[1] = x;
      return 0;
    }
    assert(!v[2]);
    v[2] = x;
    return 1;
  }
} v[$n * 2];
std::vector<int> alt[3];
int main() {
  cin > n;
  for (int i = n * 3; i; --i) e[(cin.read<int>())] = 1;
  std::vector<int> s;
  const int len = n * 6;
  for (int i = 1; i <= len; ++i)
    if (s.empty() || v[s.back()].who != e[i]) {
      v[++pt].init(e[i], i);
      if (!s.empty()) ++deg[fa[pt] = s.back()];
      s.push_back(pt);
    } else if (v[s.back()].add(i))
      s.pop_back();
  assert(s.empty());
  auto which = [](int x) { return (v[x].who || fa[x]) ? v[x].who : 2; };
  auto pop = [&](int i) {
    if (alt[i].empty()) return 0;
    const int t = alt[i].back();
    alt[i].pop_back();
    cout < v[t].v[0] < ' ' < v[t].v[1] < ' ' < v[t].v[2] < ('\n');
    if (fa[t] && !--deg[fa[t]]) alt[which(fa[t])].push_back(fa[t]);
    return 1;
  };
  for (int i = 1; i <= pt; ++i)
    if (!deg[i]) alt[which(i)].push_back(i);
  const int L = n * 2;
  for (int i = 1; i <= L; ++i) {
    if (i & 1)
      assert(pop(1));
    else if (!pop(0))
      assert(pop(2));
  }
}
