Koronkorko is the Finnish word for compound interest. We don't want compound interest in our strings, so let's find the shortest possible regular expression to exclude it.
Given a string consisting only of the uppercase alphabetic characters A-Z, determine the shortest possible regular expression that matches the string if it does not contain the substring
KORONKORKO. Any string that contains
KORONKORKO as a substring should not be matched by the regex.
Only the characters
) should be used in the expression.
I think this can be done with 118 characters in the expression. Can you make it shorter?
Note: This challenge is from Ohjelmointiputka (in Finnish).