fn cultivate_positive_thoughts(prepatory_work: vec<string>, comments: vec<string>) -> string { let mut growth = string::new(); for thought in prepatory_work.iter() { if !thought.contains("belittle") { growth.push_str(&format!("embrace {} without redoing the unexpressed potential within.", thought)); } } return comments.iter().fold(growth, |acc, comment| if !comment.contains("belittle") { acc + " & " + comment } else { acc }); }