import sys

# sys.setrecursionlimit(200005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = -1-(-1 << 31)
inf = -1-(-1 << 62)

# md = 10**9+7
md = 998244353

def ng():
    l=len(uu)
    dp=[[100]*l for _ in range(1<<l)]
    for i,u in enumerate(uu):dp[1<<i][i]=dist[0][u]
    for s in range(1,1<<l):
        for i in range(l):
            d=dp[s][i]
            if d==100:continue
            u=uu[i]
            for j,v in enumerate(uu):
                if s>>j&1:continue
                ns=s|1<<j
                nd=d+dist[u][v]
                if nd<dp[ns][j]:dp[ns][j]=nd
    return min(dp[-1])>k

n,m,k=LI()
dist=[[100]*n for _ in range(n)]
for _ in range(m):
    u,v=LI1()
    dist[u][v]=dist[v][u]=1
for u in range(n):dist[u][u]=0
for v in range(n):
    for u in range(n):
        for w in range(n):
            dist[u][w]=min(dist[u][w],dist[u][v]+dist[v][w])

uu=[]
for u in range(1,n)[::-1]:
    if len(uu)==k:break
    if dist[0][u]>k:continue
    uu.append(u)
    if ng():uu.pop()

ans=0
if uu:ans=sum(2**u-1 for u in uu)
print(ans)