> # include<stdio.h>
> int n,q,m,a,f[999],s;
> int main()
> {
>     while (scanf("%d%d",&n,&q),n!=0)
>     {
>           for (s=800;s>0;s--) f[s]=0;
>           while (n--)
>           {
>                 scanf("%d",&m);
>                 while (m--)
>                 {
>                       scanf("%d",&a);
>                       f[a]++;
>                 }
>           }
>           for (m=0;m<800;m++) if (f[m]>=q&&f[m]>f[s]) s=m;
>           printf("%d\n",s); 
>     }
> }