In the final step, when processing input==0 && input==1, JS treated the input as an object, so the first input could be 0, and the second input was ++ to 1, but during the handover process, it was converted to a string, so I wouldn't be able to pass it over as an object... I can't get a sense of it, so I'm leaving a post to see if I can get a hint

I know I need to do something with eval in stage 4, but I'm not sure. Can I get a hint?