from copy import deepcopy

n, m, t = map(int, input().split())
A = [[0] * n for _ in range(n)]
for _ in range(m):
    a, b = map(int, input().split())
    A[b][a] = 1
    
B = [0] * n
B[0] = 1
while t:
    if t & 1:
        C = [0] * n
        for i in range(n):
            for j in range(n):
                C[i] |= A[i][j] & B[j]
        B = C[:]
    t >>= 1
    C = [[0] * n for _ in range(n)]
    for i in range(n):
        for j in range(n):
            for k in range(n):
                C[i][j] |= A[i][k] & A[k][j]
    A = deepcopy(C)
print(sum(B))