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

class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        int[] inpt = Reader.GetInt();
        this.NodeCount = inpt[0];
        int connecterCount = inpt[1];
        int maxMove = inpt[2];

        for (int i = 0; i < connecterCount; i++)
        {
            inpt = Reader.GetInt();
            if (!roadDic.ContainsKey(inpt[0]))
            {
                roadDic.Add(inpt[0], new List<int>());
            }
            roadDic[inpt[0]].Add(inpt[1]);
            if (!roadDic.ContainsKey(inpt[1]))
            {
                roadDic.Add(inpt[1], new List<int>());
            }
            roadDic[inpt[1]].Add(inpt[0]);
        }

        ulong num = Convert.ToUInt64("1".PadLeft(61, '1'), 2);
        ulong ans = this.GetAns(1, maxMove, num);
        Console.WriteLine(ans);

    }

    private ulong GetAns(int nodeNum, int remain, ulong target)
    {
        ulong subTarget = target;
        ulong key = Convert.ToUInt64("1".PadRight(nodeNum, '0').PadLeft(61, '0'), 2);
        if (!dic.ContainsKey(nodeNum))
        {
            dic.Add(nodeNum, new Dictionary<int, Dictionary<ulong, ulong>>());
        }
        if (!dic[nodeNum].ContainsKey(remain))
        {
            dic[nodeNum].Add(remain, new Dictionary<ulong, ulong>());
        }
        if(dic[nodeNum][remain].ContainsKey(target)) {
            return dic[nodeNum][remain][target];
        }
        ulong ans = 0;
        if (remain == 0)
        {
            if ((target & key) == key)
            {
                ans = (ulong)Math.Pow(2, nodeNum - 1) - 1;
                subTarget -= key;
            }
        }
        else
        {
            ulong addNum = 0;
            if((target & key) == key) {
                addNum = (ulong)Math.Pow(2, nodeNum - 1) - 1;
                subTarget -= key;
            }
            foreach (int num in roadDic[nodeNum])
            {
                ulong ret = this.GetAns(num, remain - 1, subTarget);
                if(ret >= 0) {
                    ret += addNum;
                }
                ans = Math.Max(ans, ret);
            }
        }
        dic[nodeNum][remain].Add(target, ans);
        return ans;
    }

    private Dictionary<int, List<int>> roadDic = new Dictionary<int, List<int>>();

    private Dictionary<int, Dictionary<int, Dictionary<ulong, ulong>>> dic = new Dictionary<int,Dictionary<int,Dictionary<ulong,ulong>>>();
    private int NodeCount;

    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"



5 4 4
3 4
4 1
1 5
5 2



 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}