Here are my calculations:
1. Dead - Ukrainians say 12,000+. US CIA estimated 5-7000 a few days ago. UK intelligence thought 8,000. That's a few days ago, the numbers have gone up since then. So - let's say 7,500 dead
2. The ratio of wounded to dead in most conflicts is 3.5 to 5. Let's take the low number. 3.5. That's 26,000 wounded
3. Ukrainians report (they actually have names/ID numbers) 3,000 captured.
Add it together.
Again - 4 Russian one-star generals have been eliminated. More than a dozen colonels. You don't get such high numbers among top officers without the grunts being killed by thousands.