#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long int ull;
typedef long long int ll;
typedef pair<ll,ll> pll;
typedef long double D;
typedef complex<D> P;
#define F first
#define S second
const ll E=1e18+7;
const ll MOD=998244353;
// 1000000007;

template<typename T,typename U>istream & operator >> (istream &i,pair<T,U> &A){i>>A.F>>A.S; return i;}
template<typename T>istream & operator >> (istream &i,vector<T> &A){for(auto &I:A){i>>I;} return i;}
template<typename T,typename U>ostream & operator << (ostream &o,const pair<T,U> &A){o<<A.F<<" "<<A.S; return o;}
template<typename T>ostream & operator << (ostream &o,const vector<T> &A){ll i=A.size(); for(auto &I:A){o<<I<<(--i?" ":"");} return o;}
template<typename T>vector<T> & cset(vector<T> &A,T e=T()){for(auto &I:A){I=e;} return A;}


using Int = long long;
//BEGIN CUT HERE
template<typename T,bool directed>
struct Dinic{
  struct edge {
    int to;
    T cap;
    int rev;
    edge(){}
    edge(int to,T cap,int rev):to(to),cap(cap),rev(rev){}
  };

  vector<vector<edge> > G;
  vector<int> level,iter;

  Dinic(){}
  Dinic(int n):G(n),level(n),iter(n){}

  int add_edge(int from,int to,T cap){
    G[from].emplace_back(to,cap,G[to].size());
    G[to].emplace_back(from,directed?0:cap,G[from].size()-1);
    return G[to].back().rev;
  }

  void bfs(int s){
    fill(level.begin(),level.end(),-1);
    queue<int> que;
    level[s]=0;
    que.emplace(s);
    while(!que.empty()){
      int v=que.front();que.pop();
      for(int i=0;i<(int)G[v].size();i++){
        edge &e=G[v][i];
        if(e.cap>0&&level[e.to]<0){
          level[e.to]=level[v]+1;
          que.emplace(e.to);
        }
      }
    }
  }

  T dfs(int v,int t,T f){
    if(v==t) return f;
    for(int &i=iter[v];i<(int)G[v].size();i++){
      edge &e=G[v][i];
      if(e.cap>0&&level[v]<level[e.to]){
        T d=dfs(e.to,t,min(f,e.cap));
        if(d==0) continue;
        e.cap-=d;
        G[e.to][e.rev].cap+=d;
        return d;
      }
    }
    return 0;
  }

  T flow(int s,int t,T lim){
    T fl=0;
    while(1){
      bfs(s);
      if(level[t]<0||lim==0) break;
      fill(iter.begin(),iter.end(),0);

      while(1){
        T f=dfs(s,t,lim);
        if(f==0) break;
        fl+=f;
        lim-=f;
      }
    }
    return fl;
  }

  T flow(int s,int t){
    return flow(s,t,numeric_limits<T>::max()/2);
  }

  T cut(int s,int t,int x,int a){
    static_assert(directed, "must be directed");
    auto &e=G[x][a];
    int y=e.to;
    T ce=e.cap,cr=G[y][e.rev].cap;
    if(cr==0) return 0;
    e.cap=G[y][e.rev].cap=0;
    T cap=cr-flow(x,y,cr);
    if(x!=s&&cap!=0) flow(x,s,cap);
    if(t!=y&&cap!=0) flow(t,y,cap);
    e.cap=ce+cr;
    return cap;
  }
};
//END CUT HERE



int main(){
  int N,M;
  cin>>N>>M;
  vector<vector<int>> A(N,vector<int>(M));
  vector<vector<int>> one(N,vector<int>(M));
  vector<vector<int>> cnt(N,vector<int>(N,0));
  cin>>A;
  for(auto &I:A){for(auto &J:I){J--;}}
  for(int i=0;i<N;i++){
    for(int j=0;j<M;j++){
      cnt[i][A[i][j]/M]++;
    }
  }
  for(int i=0;i<M;i++){
    Dinic<int,true> fl(2+N+N);
    int s=2*N;
    int g=s+1;
    int c=0;
    int m=N;
    for(int j=0;j<N;j++){
      for(int k=0;k<N;k++){
        if(cnt[j][k]){fl.add_edge(c+j,m+k,1);}
      }
      fl.add_edge(s,c+j,1);
      fl.add_edge(m+j,g,1);
    }
    assert(fl.flow(s,g)==N);
    for(int j=0;j<N;j++){
      for(auto &e:fl.G[c+j]){
        if(e.cap==0 && e.to!=s){
          one[j][i]=e.to-m;
          cnt[j][e.to-m]--;
        }
      }
    }
  }

  
  
  for(int i=0;i<N;i++){
    for(int j=0;j<M;j++){
      for(int k=0;k<M;k++){
        if(A[i][k]!=-1 && A[i][k]/M==one[i][j]){
          one[i][j]=A[i][k];
          A[i][k]=-1;
          break;
        }
      }
    }
  }
  for(auto &I:one){
    for(auto &J:I){J++;}
  }
  for(auto &I:one){cout<<I<<endl;}
  for(int j=0;j<M;j++){
    vector<ll> X(N);
    for(int i=0;i<N;i++){X[i]=one[i][j];}
    sort(X.begin(),X.end());
    for(int i=0;i<N;i++){one[i][j]=X[i];}
  }
  for(auto &I:one){cout<<I<<endl;}
  

  return 0;
}


Measured memory_bytes: 760