# めぐるちゃんのを参考にしました
import itertools


def solve():
    N, M, K = map(int, input().split())

    inf = float('inf')

    dist = [[inf] * N for _ in range(N)]
    for i in range(N):
        dist[i][i] = 0

    for i in range(M):
        u, v = map(int, input().split())
        u -= 1
        v -= 1
        dist[u][v] = dist[v][u] = 1

    for k, i, j in itertools.product(range(N), repeat=3):
        dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j])

    dp = [[inf] * (K + 1) for _ in range(1 << (K + 1))]

    def check(v):
        l = len(v)

        for i in range(1 << l):
            for j in range(l):
                dp[i][j] = inf

        for i in range(l):
            dp[1 << i][i] = dist[0][v[i]]

        for i in range(1, 1 << l):
            dpi = dp[i]
            for j in range(l):
                if dpi[j] == inf:
                    continue
                for k in range(l):
                    k1 = 1 << k
                    if i & k1:
                        continue
                    ni = i | k1
                    dp[ni][k] = min(dp[ni][k], dpi[j] + dist[v[j]][v[k]])

        return any(a <= K for a in dp[(1 << l) - 1])

    ans = 0
    v = []
    for n in range(N - 1, 0, -1):
        if len(v) == K:
            break
        v.append(n)
        if check(v):
            ans += 2 ** n - 1
        else:
            v.pop()
    print(ans)


if __name__ == '__main__':
    solve()