import numpy as np


def pow_matrix_mod(x, n):
    if not n:
        return np.eye(len(x), dtype=int)
    if n % 2 == 0:
        return pow_matrix_mod(np.where((x @ x) != 0, 1, 0), n // 2)
    else:
        tmp = pow_matrix_mod(np.where((x @ x) != 0, 1, 0), (n - 1) // 2)
        return np.where((x @ tmp) != 0, 1, 0)


N, M, T = map(int, input().split())
matr = [[0] * N for _ in range(N)]
for _ in range(M):
    a, b = map(int, input().split())
    matr[a][b] = 1
matr = np.array(matr)

first = np.zeros(N, dtype=int)
first[0] = 1

ans = np.count_nonzero(first @ pow_matrix_mod(matr, T))
print(ans)