import sys
import numpy as np

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

def mult(A, B):
    C = np.dot(A, B)
    C[C >= 1] = 1
    return C

def mat_pow(A, n):
    if n == 0:
        return np.eye(len(A), dtype=np.int64)
    X = mat_pow(A, n // 2)
    X = mult(X, X)
    return mult(A, X) if n & 1 else X

N, M, T = map(int, readline().split())
A = np.zeros((N, N), np.int64)
m = map(int, read().split())
for frm, to in zip(m, m):
    A[to, frm] += 1

B = mat_pow(A, T)
ans = B[:, 0].sum()
print(ans)