////////////////////////////////////////
///  tu3 pro-con template            ///
////////////////////////////////////////
#include <cassert>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <algorithm>
#include <numeric>
#include <functional>
#include <vector>
#include <queue>
#include <string>
#include <complex>
#include <stack>
#include <set>
#include <map>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <regex>
#include <type_traits>
#include <mutex>
using namespace std;

//// MACRO ////
#define countof(a) (sizeof(a)/sizeof(a[0]))

#define REP(i,n) for (int i = 0; i < (n); i++)
#define RREP(i,n) for (int i = (n)-1; i >= 0; i--)
#define FOR(i,s,n) for (int i = (s); i < (n); i++)
#define RFOR(i,s,n) for (int i = (n)-1; i >= (s); i--)
#define pos(c,i) c.being() + (i)
#define allof(c) c.begin(), c.end()
#define aallof(a) a, countof(a)
#define partof(c,i,n) c.begin() + (i), c.begin() + (i) + (n)
#define apartof(a,i,n) a + (i), a + (i) + (n)
typedef unsigned int uint;
typedef long long llong;
typedef unsigned long long ullong;

#define EPS 1e-9
#define INF (1L << 28)
#define LINF (1LL << 60)

#define PREDICATE(t,a,exp) [&](const t & a) -> bool { return exp; }
#define COMPARISON_T(t) bool(*)(const t &, const t &)
#define COMPARISON(t,a,b,exp) [&](const t & a, const t & b) -> bool { return exp; }
#define CONVERTER(TSrc,t,TDest,exp) [&](const TSrc &t)->TDest { return exp; }

inline int sign_of(double x) { return abs(x) < EPS ? 0 : x > 0 ? 1 : -1; }
inline bool inRange(int val, int min, int max) { return val >= min && val < max; }
inline bool inRange(double val, double min, double max) { return val - min > -EPS && val - max < EPS; }
inline bool inRange(int x, int y, int W, int H) { return x >= 0 && x < W && y >= 0 && y < H; } // W,H含まない

template <class T> struct vevector : public vector<vector<T>> { vevector(int n = 0, int m = 0, const T &initial = T()) : vector<vector<T>>(n, vector<T>(m, initial)) { } };
template <class T> struct vevevector : public vector<vevector<T>> { vevevector(int n = 0, int m = 0, int l = 0, const T &initial = T()) : vector<vevector<T>>(n, vevector<T>(m, l, initial)) { } };
template <class T> struct vevevevector : public vector<vevevector<T>> { vevevevector(int n = 0, int m = 0, int l = 0, int k = 0, const T &initial = T()) : vector<vevevector<T>>(n, vevevector<T>(m, l, k, initial)) { } };

//// i/o helper ////

namespace std {
	template <class T1, class T2> inline istream & operator >> (istream & in, pair<T1, T2> &p) { in >> p.first >> p.second; return in; }
	template <class T1, class T2> inline ostream & operator << (ostream &out, const pair<T1, T2> &p) { out << p.first << " " << p.second; return out; }
}
template <class T> T read() { T t; cin >> t; return t; }
template <class T> vector<T> read(int n) { vector<T> v; REP(i, n) { v.push_back(read<T>()); } return v; }
template <class T> vevector<T> read(int n, int m) { vevector<T> v; REP(i, n) v.push_back(read<T>(m)); return v; }
template <class T> vector<T> readjag() { return read<T>(read<int>()); }
template <class T> vevector<T> readjag(int n) { vevector<T> v; REP(i, n) v.push_back(readjag<T>()); return v; }

template <class T> struct iter_pair_t { T beg, end; };
template <class T> iter_pair_t<T> iter_pair(T beg, T end) { return iter_pair_t<T>{beg, end}; }
template <class T> ostream & operator << (ostream &out, const iter_pair_t<T> &v)
{
	std::copy(v.beg, v.end, ostream_iterator<typename decltype(v.beg)::reference>(out, " "));
	return out;
}
template <class T1> ostream & operator << (ostream &out, const vector<T1> &v) { return out << iter_pair(begin(v), end(v)); }
template <class T1> ostream & operator << (ostream &out, const set<T1> &v) { return out << iter_pair(begin(v), end(v)); }
template <class T1, class T2> ostream & operator << (ostream &out, const map<T1, T2> &v) { return out << iter_pair(begin(v), end(v)); }

struct _Reader { istream &cin; template <class T> _Reader operator ,(T &rhs) { cin >> rhs; return *this; } };
struct _Writer { ostream &cout; bool f{ false }; template <class T> _Writer operator ,(const T &rhs) { cout << (f ? " " : "") << rhs; f = true; return *this; } };
#define READ(t,...) t __VA_ARGS__; (_Reader{cin}), __VA_ARGS__
#define WRITE(...) (_Writer{cout}), __VA_ARGS__; cout << endl
#define DEBUG(...) (_Writer{cerr}), __VA_ARGS__; cerr << endl

void solve();
int main()
{
	cin.tie(0);
	ios_base::sync_with_stdio(false);
	cout << setprecision(std::numeric_limits<double>::max_digits10);
	solve();

	return 0;
}

// warshall_floyd //
template <class COST>
void warshall_floyd(vector<vector<COST>> &cost)
{
	size_t n = cost.size();
	REP(k, n) REP(i, n) REP(j, n) cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
}

#ifdef _MSC_VER
inline uint __builtin_ctz(uint x) { unsigned long r; _BitScanForward(&r, x); return r; } // if x == 0 returns undefined.
inline ullong __builtin_ctzll(unsigned long long x) { return x & 0xFFFFFFFF ? __builtin_ctz(x & 0xFFFFFFFF) : __builtin_ctz(x >> 32) + 32; }
#endif

// uint bit permutation //
struct BitPermutation
{
	using TVal = unsigned int;
	static int bsf(uint x) { return x ? __builtin_ctz(x) : -1; }
	static int bsf(ullong x) { return x ? __builtin_ctzll(x) : -1; }
	static TVal next_bit_permutation(TVal x) {
		TVal t = x | (x - 1);
		TVal p = (~t & -~t) - 1;
		return (t + 1) | (p >> (bsf(x) + 1));
	}

	struct it {
		TVal val;
		TVal operator *() const { return val; }
		it& operator ++() { val = next_bit_permutation(val); return *this; }
		bool operator != (it o) const { return val != o.val; }
	};

	it s, e;
	BitPermutation(int n, int k)
		: s{ (TVal(1) << k) - 1 }
		, e{ k > 0 ? TVal(1) << n | ((TVal(1) << (k - 1)) - 1) : next_bit_permutation(0) }
	{
		assert(n >= k);
	}
	it begin() const { return s; }
	it end() const { return e; }
};

using TCost = int;
template <class TDistance>
int HeldKarp(int N, TDistance g, int start = 0, bool needToReturnStart = false)
{
	vevector<TCost> dp(1 << N, N, INF);
	dp[1 << start][start] = 0;

	FOR(i, 1, N)
	{
		for (int n : BitPermutation(N, i))
		{
			REP(from, N)
			{
				if (dp[n][from] >= INF) { continue; }
				REP(to, N)
				{
					int next = n | 1 << to;
					int dist = dp[n][from] + g(from, to);
					if (dist < dp[next][to] )
					{
						dp[next][to] = dist;
					}
				}
			}
		}
	}

	if (needToReturnStart)
	{
		return dp[(1 << N) - 1][start];
	}
	else
	{
		return *min_element(allof(dp[(1 << N) - 1]));
	}
}


////////////////////
/// template end ///
////////////////////

void solve()
{

	READ(int, N, M, K);

	vevector<int> routes(N, N, INF);
	REP(i, M)
	{
		READ(int, U, V);
		routes[U - 1][V - 1] = 1;
		routes[V - 1][U - 1] = 1;
	}

	warshall_floyd(routes);

	vector<int> cand;
	FOR(i, 1, N)
	{
		if (routes[0][i] <= K)
		{
			cand.push_back(i);
		}
	}
	sort(allof(cand), greater<int>());

	N = cand.size();

	vector<int> targets; 
	targets.push_back(0);
	llong ans = 0;

	for (auto c : cand)
	{
		targets.push_back(c);
		int cost = HeldKarp(targets.size(), [&](int i, int j) { return routes[targets[i]][targets[j]]; });

		if (cost > K)
		{
			targets.pop_back();
			continue;
		}

		llong tmp = 0;
		for (auto id : targets)
		{
			tmp += (1ll << id) - 1;
		}
		ans = max(ans, tmp);
		if (targets.size() >= K + 1)
		{
			break;
		}
	}
	WRITE(ans);
}