It’s the one on the left. We’re allowed any calculator that’s not programmable and cannot store text. The Elektronika can be programmed though it cannot store a program when turned off.
Nevermind the Casio’s ability to solve, integrate, derivate, deal with complex numbers and matrices and more
If you can write and store an arbitrary program then it’s pretty simple to write a “program” that just prints out an answer key/cheat sheet on demand, which is generally the issue that these kinds of rules are trying to solve.
Having a tool that can solve complex problems and knowing how to use it is not an issue that needs to be solved.
They forced us to buy expensive graphing calculators for geometry, trig, and pre-calc in high school but we never used them to actually graph anything in any of those years. Didn’t even teach us how to use them or why they’re useful. But because I liked tech and was curious, I did learn TI’s specific flavor of basic because I got one. Ended up writing a program that just stored and printed out the formula we were studying because I always had trouble remembering them offhand. Used the program for reference during tests but in the end I don’t think it was really that wrong, because I’d have to know which calculations to implement based on the questions anyways. I think I lucked out growing up in the time that I did lol.