I agree that it's enough to know well one low level (or medium level) language and one high level language. For me, I decided a while ago that the two language

I agree that it's enough to know well one low level (or medium level) language and one high level language. For me, I decided a while ago that the two languages will be Java and Javascript. It was an easy decision since I use those languages at work, they both have healthy and growing ecosystems, and active communities.