#include <bits/stdc++.h>
using namespace std;
// #define int long long
// #define double long double
#define rep(i,a,b) for(int i=(int)(a); i<(int)(b); ++i)
#define repeq(i,a,b) for(int i=(int)(a); i<=(int)(b); ++i)
#define rrep(i,a,b) for(int i=(int)(a)-1; i>=(int)(b); --i)
#define rrepeq(i,a,b) for(int i=(int)(a); i>=(int)(b); --i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
template<typename T> using Graph = vector<vector<T>>;
template<typename T> using Spacial = vector<vector<vector<T>>>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template<typename T> using greater_priority_queue = priority_queue<T, vector<T>, greater<T>>;
const int MOD = 1e9+7;
const int MOD2 = 998244353;
// const double EPS = 1e-9;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
string interval[2] = {" ", "\n"}; // {" ", "\n"}

template<typename T> struct is_plural : false_type{};
template<typename T1, typename T2> struct is_plural<pair<T1, T2>> : true_type{};
template<typename T> struct is_plural<vector<T>> : true_type{};
template<typename T> struct is_plural<complex<T>> : true_type{};
template<> struct is_plural<string> : true_type{};

template<typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << " " << p.second; }
template<typename T> istream &operator>>(istream &is, vector<T> &vec) { for(auto itr = vec.begin(); itr != vec.end(); ++itr) is >> *itr; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { if(vec.empty()) return os; bool pl = is_plural<T>(); os << vec.front(); for(auto itr = ++vec.begin(); itr != vec.end(); ++itr) os << interval[pl] << *itr; return os; }

bool CoutYN(bool a, string y = "Yes", string n = "No") { cout << (a ? y : n) << "\n"; return a; }

template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

long long modpow(int a, long long n, int mod = MOD) { long long ret = 1; do { if(n & 1) ret = ret * a % mod; a = 1LL * a * a % mod; } while(n >>= 1); return ret; }

template<typename T> T GCD(T a, T b) { return b ? GCD(b, a%b) : a; }
template<typename T> T LCM(T a, T b) { return a / GCD(a, b) * b; }

template<typename T1, typename T2> bool CompareBySecond(pair<T1, T2> a, pair<T1, T2> b) { return a.second != b.second ? a.second < b.second : a.first < b.first; }
template<typename T1, typename T2> bool CompareByInverse(pair<T1, T2> a, pair<T1, T2> b) { return a.first != b.first ? a.first < b.first : a.second > b.second; }


/* -------- <templates end> -------- */


void solve() {
  int n, m; cin >> n >> m;
  Graph<int> a(n, vi(m)); cin >> a;

  Spacial<int> g(n, Graph<int>(n));
  rep(i,0,n) {
    for(auto &x : a[i]) {
      g[i][(x - 1) / m].emplace_back(x);
    }
  }

  Graph<int> b(n);

  rep(_,0,m) {
    vector<set<int>> rest(n);
    rep(i,0,n) {
      rep(j,0,n) {
        if(!g[i][j].empty()) {
          rest[i].emplace_hint(rest[i].end(), j);
        }
      }
    }

    vi pos(n, -1);
    vi val(n, -1);

    rep(i,0,n) {
      queue<int> q;
      q.emplace(i);
      vi from(n, -2);

      while(!q.empty()) {
        int v = q.front(); q.pop();

        for(auto x : rest[v]) {
          if(from[x] != -2) continue;

          from[x] = val[v];

          if(pos[x] == -1) {
            pos[x] = i;

            while(from[x] != -1) {
              swap(pos[x], pos[from[x]]);
              val[pos[x]] = x;
              rest[pos[x]].erase(x);
              rest[pos[x]].emplace(from[x]);
              x = from[x];
            }

            val[i] = x;
            rest[i].erase(x);
            v = -1;
            break;
          }

          q.emplace(pos[x]);
        }

        if(v == -1) break;
      }
    }

    rep(i,0,n) {
      b[i].emplace_back(g[i][val[i]].back());
      g[i][val[i]].pop_back();
    }
  }

  Graph<int> c(n);

  rep(j,0,m) {
    rep(i,0,n) {
      c[(b[i][j] - 1) / m].emplace_back(b[i][j]);
    }
  }

  cout << b << '\n' << c << endl;
}


/* -------- <programs end> -------- */


signed main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  solve();
  return 0;
}


Measured memory_bytes: 4588