#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int dp[17][1 << 17], dis[61][61], INF = INT_MAX;

int main(){
    int N, M, K;
    cin >> N >> M >> K;
    rep(i, N + 1)rep(j, N + 1)dis[i][j] = INF;
    rep(i, M){
        int u, v; cin >> u >> v;
        dis[u][v] = dis[v][u] = 1;
    }
    FOR(k, 1, N + 1)FOR(u, 1, N + 1)FOR(v, 1, N + 1){
        if(dis[u][k]!=INF&&dis[k][v]!=INF)smin(dis[u][v],dis[u][k]+dis[k][v]);
    }
    vi p{1};
    for(int i = N; i >= 2; --i){
        p.push_back(i);
        int m = sz(p);
        rep(j, m)rep(k, 1 << m)dp[j][k] = INF;
        dp[0][1] = 0;
        rep(S, 1 << m){
            rep(j, m)if(dp[j][S]<K){
                rep(k, m)if(j != k){
                    int d = dis[p[j]][p[k]];
                    if(d!=INF)smin(dp[k][S | 1 << k], dp[j][S] + d);
                }
            }
        }
        int ok = 0;
        rep(j, m)ok |= dp[j][(1 << m) - 1] <= K;
        if(!ok)p.pop_back();
    }
    ll ans = 0;
    each(k, p)ans += (1ll << (k - 1)) - 1;
    cout << ans << endl;
}