The conversation between human and AI assistant.
[|Human|] Given a string and a search term, find the index of the first occurrence of the search term in the string.
[|AI|] The index of the first occurrence of the search term 'wor' in the string 'hello world' is 6.
[|Human|] 
Given a string and a search term, find the index of the first occurrence of the search term in the string.