using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class Program
{
    public void Solve()
    {
        var sc = new Scanner();
        int n = sc.NextInt();
        List<S> l = new List<S>();
        for (int i = 0; i < n; i++)
        {
            int p = sc.NextInt();
            for (int j = 0; j < p; j++)
            {
                l.Add(new S(i, j, sc.NextInt()));
            }
        }

        l.Sort((a, b) =>
        {
            if (a.J == b.J)
            {
                return a.I.CompareTo(b.I);
            }

            return a.J.CompareTo(b.J);
        });
        
        Console.WriteLine(string.Join(" ",l.Select(s=>s.Num)));
    }

    public static void Main(string[] args)
    {
        new Program().Solve();
    }
}

struct S
{
    public int I, J, Num;

    public S(int i, int j, int n)
    {
        I = i;
        J = j;
        Num = n;
    }
}

class Scanner
{
    public Scanner()
    {
        _pos = 0;
        _line = new string[0];
    }

    const char Separator = ' ';
    private int _pos;
    private string[] _line;

    #region スペース区切りで取得

    public string Next()
    {
        if (_pos >= _line.Length)
        {
            _line = Console.ReadLine().Split(Separator);
            _pos = 0;
        }

        return _line[_pos++];
    }

    public int NextInt()
    {
        return int.Parse(Next());
    }

    public long NextLong()
    {
        return long.Parse(Next());
    }

    public double NextDouble()
    {
        return double.Parse(Next());
    }

    #endregion

    #region 型変換

    private int[] ToIntArray(string[] array)
    {
        var result = new int[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = int.Parse(array[i]);
        }

        return result;
    }

    private long[] ToLongArray(string[] array)
    {
        var result = new long[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = long.Parse(array[i]);
        }

        return result;
    }

    private double[] ToDoubleArray(string[] array)
    {
        var result = new double[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = double.Parse(array[i]);
        }

        return result;
    }

    #endregion

    #region 配列取得

    public string[] Array()
    {
        if (_pos >= _line.Length)
            _line = Console.ReadLine().Split(Separator);

        _pos = _line.Length;
        return _line;
    }

    public int[] IntArray()
    {
        return ToIntArray(Array());
    }

    public long[] LongArray()
    {
        return ToLongArray(Array());
    }

    public double[] DoubleArray()
    {
        return ToDoubleArray(Array());
    }

    #endregion
}