## Editorial for Mock CCC '22 1 S3 - IU

Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.

For 1 mark, recursive backtracking should work.

For 5 marks, compute the longest common subsequence of the given string and the desired string.

For full marks, count the number of times IU appears. The answer is minus that.