import sys
from collections import deque

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N, M, K = map(int, readline().split())
m = map(int, read().split())

G = [[] for _ in range(N)]
for u, v in zip(m, m):
    u -= 1
    v -= 1
    G[u].append(v)
    G[v].append(u)

def bfs(v):
    dist = [-1] * N
    q = deque([v])
    dist[v] = 0
    while q:
        v = q.popleft()
        for w in G[v]:
            if dist[w] != -1:
                continue
            dist[w] = dist[v] + 1
            q.append(w)
    return dist

dist_mat = [bfs(v) for v in range(N)]

def extract_subgraph(A):
    assert A[0] == 0
    mat = []
    for i in A:
        mat.append([dist_mat[i][j] for j in A])
    return mat

def min_hamilton_path(A):
    mat = extract_subgraph(A)
    n = len(A)
    INF = K + 1
    dp = [[INF] * n for _ in range(1 << n)]  # (部分集合, 最後の頂点)
    dp[1][0] = 0
    for s in range(1, 1 << n, 2):
        for i in range(n):
            x = dp[s][i]
            if x == INF:
                continue
            for j in range(1, n):
                if s & (1 << j):
                    continue
                t = s ^ (1 << j)
                y = x + mat[i][j]
                if dp[t][j] > y:
                    dp[t][j] = y
    return min(dp[-1])

A = [0]
for n in range(N - 1, 0, -1):
    A.append(n)
    if min_hamilton_path(A) > K:
        A.pop()

answer = sum((1 << x) - 1 for x in A)
print(answer)