import numpy as np
n, m, t = map(int, input().split())
p = np.zeros((n, n), dtype = np.bool)
for _ in range(m):
  a, b = map(int, input().split())
  p[b][a] = 1
q = np.zeros((n, 1), dtype = np.bool)
q[0][0] = 1
print(sum(i[0] for i in (q @ np.linalg.matrix_power(p, n))))