Liquid: ifelse not working and printing var in the body

I'm trying to create a home page for a simple blog with HTML and CSS. For the blog posts, I've created 2 types of cards: blog-card and blog-card alt, one to the left and one to the right, and they are meanted to be alterneted. So I did the following code:

But instead of alternating the card format, all the cards are on the left (following blog-card) and the var iter is being printed on the screen. What I have to do? Thanks in advace!