#include <fstream>
#include <iostream>
#include <algorithm>
#define N 105
using namespace std;
ifstream fin(".in");
ofstream fout(".out");
///778
int a[N][N],n,m;
int fr[4*N];
int main()
{
  int vmin=10005, vmax=-1;
  int i,j;
  cin>>n>>m;
  for(i=1; i<=n; ++i)
    for( j=1; j<=m; ++j)
      {
          cin>>a[i][j];
      }
   ///crearea unui vector de frecventa manual
   int k=0,x;
   bool gasit;
   ///liniile 1 si n
   for(j=1;j<=m;j++)
   {
      x=a[1][j];///linia 1
      if(k==0) fr[++k]=x;
      else
      {
          gasit=0;
          for(i=1;i<=k && !gasit; ++i)
            if(fr[i]==x)gasit=1;
          if(gasit==0)fr[++k]=x;
      }
      x=a[n][j];///linia n
      if(k==0) fr[++k]=x;
      else
      {
          gasit=0;
          for(i=1;i<=k && !gasit; ++i)
            if(fr[i]==x)gasit=1;
          if(gasit==0)fr[++k]=x;
      }
   }
   ///coloana 1 si m
   for(i=2;i<m;i++)
   {
       x=a[i][1];///coloana 1
      if(k==0) fr[++k]=x;
      else
      {
          gasit=0;
          for(j=1;j<=k && !gasit; ++j)
            if(fr[j]==x)gasit=1;
          if(gasit==0)fr[++k]=x;
      }
      x=a[i][m];///coloana m
      if(k==0) fr[++k]=x;
      else
      {
          gasit=0;
          for(j=1;j<=k && !gasit; ++j)
            if(fr[j]==x)gasit=1;
          if(gasit==0)fr[++k]=x;
      }
   }

  sort(fr+1, fr+k+1);

  for(i=1;i<=k;i++)
    if(!fr[i])cout<<fr[i]<<" ";
  return 0;
}