def m(a,b):
  r=[[0]*len(b[0]) for i in range(len(a))]
  for i in range(len(a)):
    for k in range(len(b)):
      for j in range(len(b[0])):
        r[i][j]|=(a[i][k]&b[k][j])
  return r

def p(a,n):
  r=[[0]*len(a) for i in range(len(a))]
  b=[]
  for i in range(len(a)):
    r[i][i]=1
    b.append(a[i][:])
  l=n
  while l>0:
    if l&1:
      r=m(b,r)
    b=m(b,b)
    l>>=1
  return r

N,M,T=map(int,input().split())
A=[[0]*N for i in range(N)]
for i in range(M):
  a,b=map(int,input().split())
  A[a-1][b-1]=1
B=[[0]*N for i in range(N)]
B[0][N-1]=1
C=m(p(A,T),B)
print(sum([C[i][-1] for i in range(N)]))