《宋书·列传·卷九十五》
刘裕回到东方，佛佛便入侵北地。
高祖东还，即入寇北地。
When Liu Yu returned to the east, Bobo invaded northern areas.
<s>[INST] Rewrite the following English passage in the style of Classical Chinese: When Liu Yu returned to the east, Bobo invaded northern areas. [/INST] 高祖东还，即入寇北地。</s>
Rewrite the following English passage in the style of Classical Chinese: When Liu Yu returned to the east, Bobo invaded northern areas.
user
高祖东还，即入寇北地。
assistant