INF = 10 ** 19
n, m, t = map(int, input().split())
mat = [[INF] * n for _ in range(n)]
for _ in range(m):
    a, b = map(int, input().split())
    mat[a][b] = 1
res = [[INF] * n for _ in range(n)]
for i in range(n):
    res[i][i] = 0
while t > 0:
    if t & 1:
        tmp = [[INF] * n for _ in range(n)]
        for i in range(n):
            for j in range(n):
                for k in range(n):
                    tmp[i][j] = min(tmp[i][j], res[i][k] + mat[k][j])
        res = [row[:] for row in tmp]
    tmp = [[INF] * n for _ in range(n)]
    for i in range(n):
        for j in range(n):
            for k in range(n):
                tmp[i][j] = min(tmp[i][j], mat[i][k] + mat[k][j])
    mat = [row[:] for row in tmp]
    t //= 2
ans = 0
for i in range(n):
    if res[0][i] < INF:
        ans += 1
print(ans)