import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)


def mat_mul(A, B):
    res = [[0] * len(B[0]) for _ in range(len(A))]
    for i in range(len(A)):
        for k in range(len(A[0])):
            for j in range(len(B[0])):
                res[i][j] |= (A[i][k] & B[k][j])
    return res


def mat_pow(A, n):
    size = len(A)
    res = [[0] * size for _ in range(size)]
    for i in range(size):
        res[i][i] = 1
    while n:
        if n & 1:
            res = mat_mul(res, A)
        A = mat_mul(A, A)
        n >>= 1
    return res


N, M, T = map(int, input().split())
deg = [0] * N
A = [[0]*(N+1) for _ in range(N+1)]
for _ in range(M):
    a, b = map(int, input().split())
    deg[a] += 1
    A[a][b] = 1
for i in range(N):
    if not deg[i]:
        A[i][N] = 1

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