Definition: You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").
Input: Paragraph- Sent 1: Tokugawa Takes All: When Hideyoshi died in 1598, he hoped to have his five-year-old son continue his “dynasty,” initially under the tutelage of five regents.
Sent 2: But one of the regents was Ieyasu Tokugawa, who had been biding his time at Edo for 12 years, nurturing dynastic ambitions of his own.
Sent 3: Of the cunning, ruthless triumvirate that came out on top at the end of the country’s century of civil war, Tokugawa was without doubt the most patient, the most prudent — and most treacherous.
Sent 4: He moved quickly to eliminate his strongest rivals, crushing them in 1600 at the great Battle of Sekigahara (near modern Nagoya).
Sent 5: During its subsequent two and a half centuries of rule from the new capital established at Edo, the Tokugawa organized a tightly controlled coalition of some 260 daimyo in strategic strongholds throughout the country.
Sent 6: The allegiance of this highly privileged and prestigious group was ensured by cementing their ethical principles in the code of bushido, “the way of the warrior”: loyalty to one’s master, defense of one’s status and honor, and fulfillment of all obligations.
Sent 7: Loyalty was further enforced by holding the vassals’ wives and children hostage in Edo.
Sent 8: All roads into Edo, the most famous being the Tokaido Highway, had checkpoints for guns coming in and for wives going out.
Sent 9: One of the most effective ways of keeping a tight rein on the country was to cut it off from the outside world, to keep Japan Japanese.
Sent 10: At first, Ieyasu Tokugawa was eager to promote foreign trade.
Sent 11: He wanted silk and encouraged the Dutch and British as good, nonproselytizing Protestants just interested in trade.
Sent 12: But he didn’t like the Portuguese and Spanish Catholic missionaries, who he felt were undermining traditional Japanese values.
Sent 13: He banned their activities in 1612 and two years later ordered the expulsion of all missionaries and unrepentant Japanese converts.
Sent 14: Executions and torture followed.
Sent 15: Converts were forced to renounce their faith by trampling crucifixes and effigies of Jesus and Mary.
Sent 16: The Catholic Church has counted 3,125 martyrs in Japan from 1597 (beginning under Hideyoshi) to 1660.
Sent 17: In 1635 the Japanese were forbidden, on pain of death, to attempt to travel abroad, and Japanese citizens already overseas were prevented from returning, in case they brought back subversive Christian doctrines.
Sent 18: Western books were banned, as were Chinese books that mentioned Christianity. 
Question: What was one cruel way in which the Bushido Code was enforced?.
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
6, 7.