Kids get infinite registers and no restrictions on stack ordering. Programmers are constrained to solving it with one register and restrictions on stack put operations.
I had enough colleagues unable to type exactly what they asked me into whatever search engine they preferred to accept your statement. If you don't know how to use a search engine go ask for another job.
"Hey pancake, how do I run all tests via gradle?"
Open your browser, head to Google and type "run all tests in gradle"
Did you guys find this hard? There are only four possible ways to move a ring, two of which are disallowed by the rules. Out of the remaining two, one of them is simply undoing what you just did.