#include <iostream>
using namespace std;

int main()
{
	int a[501][501];
	int i,j,n,d,flag[501],k;
	while (1)
	{
		memset(flag,0,501*sizeof(int));
		
	cin>>n>>d;
	if (n==0&&d==0)
		break;
	else
      for (i=0;i<d;i++)
	  {
		  for (j=0;j<n;j++)
			  cin>>a[i][j];
	  }
	  for (j=0;j<n;j++)
	  {
		  
			  for (k=1;k<d;k++)
			  {
			  if (a[0][j]==a[k][j]&&a[0][j]!=0)
				  flag[j]+=1;
			  else
				  flag[j]+=0;
			  }
		  
	  }
	 for (j=0;j<n;j++)
	 {
		 if (flag[j]==(d-1))
		 {
			  cout<<"yes"<<endl;
		 break;
		 }
		 else if(j!=(n-1))
			 continue;
		 else
		 cout<<"no"<<endl;
	 }
	   
	}
	return 0;

}