I have the exact same issue with failing tests 5, 14, and 15. I didn't know anything about upper limits of data types so I am going to research further to see if I can find anything. Did you figure this one out? I don't want the answer just any guidance in the right direction if you have it :-)

Issue's are kata-related, for help with code use question's. You should also format your code correctly because it's impossible to tell what your code looks like with whitespace.

this code run as description wanted to run

Not at all. You're not placing second char at the end of the word, and you're not keeping chars at the indices [2; len(word)-2] at their original place. Maybe there're more problems, but it's hard to work out what this unreadable code does.