Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.

What is cost engineers no no scratch that what is an obvious source for cost engineers?
What is an obvious source for cost engineers?

What British mathematician took pride in doing work that he felt had no cryptography benefit, no no sorry, mathematical?
What British mathematician took pride in doing work that he felt had no mathematical benefit?

Where was the or no make that when was the Fresno County Courthouse demolished?
When was the Fresno County Courthouse demolished?