"""bit並列化"""
import sys
import numpy as np

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

K = 60


def mult(A, B):
    N = len(A)
    C = np.zeros_like(A)
    # A[i,j] == 1 のとき、 C[i,:] |= B[j,:] となるので
    for j in range(N):
        idx = A[:, j // K] & (1 << j % K) > 0
        C[idx] |= B[j]
    return C


def mat_pow(A, n):
    N = len(A)
    if n == 1:
        return A
    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 // K + 1), np.int64)
m = map(int, read().split())
for frm, to in zip(m, m):
    for to in range(N):
        A[frm, to // K] |= 1 << to % K

B = mat_pow(A, T)
ans = 0
for x in B[0]:
    ans += bin(x).count('1')
print(ans)