The conversation between human and AI assistant.
[|Human|] Rewrite the following sentence to make it more concise:

He was not able to understand the intricate details of the problem, so he decided to call for assistance.
[|AI|] He couldn't grasp the problem's complexity, so he sought help.
[|Human|] 
Rewrite the following sentence to make it more concise:

He was not able to understand the intricate details of the problem, so he decided to call for assistance.