#include <bits/stdc++.h>
using namespace std;

int main() {
    int N, M, K;
    cin >> N >> M >> K;
    vector<vector<int>> d(N, vector<int>(N, 100));
    for (int i = 0; i < M; i++) {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        d[a][b] = 1;
        d[b][a] = 1;
    }

    for (int k = 0; k < N; k++) {
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
            }
        }
    }

    vector<int> use{0};
    for (int i = N - 1; i > 0; i--) {
        sort(use.begin(), use.end());
        vector<int> tmp = use;
        tmp.push_back(i);
        sort(tmp.begin(), tmp.end());
        bool flag = false;
        do {
            int cost = 0;
            for (int j = 0; j < (int)tmp.size() - 1; j++) {
                cost += d[tmp[j]][tmp[j + 1]];
            }
            if (cost <= K)
                flag = true;
        } while (next_permutation(tmp.begin() + 1, tmp.end()));
        if (flag) {
            use = tmp;
        }
        if ((int)use.size() == K + 1) {
            break;
        }
    }

    long long ans = 0;
    for (auto& x : use) {
        ans += (1ll << x) - 1;
    }
    cout << ans << endl;
}