lso it is not accurate to say that the USSR struggled to adopt computers. In the 1990s, after the fall of the USSR, many of the top academics emigrated from Russia and other post-Soviet countries instantly received faculty positions in computer science and mathematics departments in the US and other Western academia. This should give you an idea of how strong the fundamental research there existed in the USSR, and how highly their skills were sought after in the West.

There’s a difference between research and implementation on a large scale. I’m talking about the latter. I haven’t been able to find much beyond lib sources, unfortunately, but what I’ve read indicates that the USSR had around 10000 computers at a time when the US had over 1 million.