#include <stdio.h>
#include <stdlib.h>

#define MAXNR 200000
#define MAXN 1000000

int v[MAXNR + 1];
int frecv[MAXN + 1];

int main()
{
    FILE *fin, *fout;
    fin = fopen("proiecte.in", "r");
    fout = fopen("proiecte.out", "w");
    int N, M, i, j, nr, maj, cate, maxi = 0;
    fscanf(fin, "%d%d", &N, &M);
    for (i = 1; i <= M; i++)
    {
        fscanf(fin, "%d", &nr);
        for (j = 1; j <= nr; j++)
        {
            fscanf(fin, "%d", &v[j]);
        }
        maj = v[1];
        cate = 1;
        for (j = 2; j <= nr; j++)
        {
            if (v[j] == maj)
            {
                cate++;
            }
            else
            {
                cate--;
                if (cate == -1)
                {
                    maj = v[j];
                    cate = 1;
                }
            }
        }
        frecv[maj]++;
        if (frecv[maj] > maxi)
        {
            maxi = frecv[maj];
        }
    }
    for (i = 1; i <= N; i++)
    {
        if (frecv[i] == maxi)
        {
            fprintf(fout, "%d ", i);
        }
    }
    fclose(fin);
    fclose(fout);
    return 0;
}