import java.util.Scanner;
public class Main {
public static void main(String[] args){
	  int N=0,M=0;
	  Scanner scan=new Scanner(System.in);
	  while((N=scan.nextInt())!=0&& (M=scan.nextInt())!=0){
      int max=0,second=0;
	  int[] plays=new int[10001];
	  for(int i=0;i<plays.length;i++)
		  plays[i]=0;
	  for(int i=0;i<N*M;i++){
		  int temp=scan.nextInt();
		  plays[temp]++;
	  }
	  max=plays[1];
	  second=plays[1];
	  for(int i=2;i<plays.length;i++){
		 if(plays[i]>max){
		     second=max;
			 max=plays[i];
		 }
		 else if(plays[i]>second){
			 second=plays[i];
		 }
	  }
	  for(int i=1;i<plays.length;i++){
		  if(plays[i]==second)
			  System.out.print(i+" ");
	  }
	  System.out.println();
  }
}
}