Input (grade 13): What began as a chiefdom in the Samhan confederacies, once allied with China, Silla eventually conquered the other two kingdoms, Baekje in 660 and Goguryeo in 668.
Output (grade 9): Finally, Silla conquered Baekje and Goguryeo in 660 and 668 each by making a union with Tang, the ancient China country.