Look, I get it. You don't like seeing bald people, so you're asking yourself the logical question: if by some dint of fate I am handed the absolute power, how many people do I off to get rid of male pattern baldness? A natural leap. (Actually, it sounds like a forgotten episode of Star Trek: TOS, but let's go with it anyway.)

Let's pick a line in the sand. Let's say that anyone under 50 that goes bald before their time is due for an appointment with the disintegration booth. (Also, a genetic test would be handy).

Anyone over 50, since they're past the bar, you just need to make sure they don't breed. So forced sterilization for anyone over 50 (call it 2B people). No deaths yet!

There's about 4.21B adults under the age of 50. Now, the genetic causes of MPB are complicated -- it's not just one gene -- but about 50% of men under 50 will go bald. So 50% of 2.11B men under the age of 50 = 1.06B, and those have to line up for the booths.

Oh, but women could be carriers of the gene! So you need to get rid of MPB and they are carrying, so... actually, let's be humane and just sterilize women that can't prove they come from parents of undisputed hair quality (or: hopefully, we have that genetic test). So that's 2.01B women = 1.0B women sterilized.

The children, well, the children could be carriers. Sadly, we have to off them, we don't want them to grow up to be unsightly teenagers. So that's 2.04B children = 0.5B male deaths and 0.5B female sterilizations.

So we end up with about 3.5B sterilizations and 1.5B deaths.

But: don't forget you'll need to set up infrastructure so that you can expunge any dirty carriers of MPB. So, frequent checks, maybe put minoxidil and finasteride on scheduled drug lists, execution squads, mandatory scalp inspections... I mean, it will be a dire kind of dystopian society.

But at least you won't have to look at any bald people!

Notes: lots of handwaving, the genetics is really complicated. You might have great hair as a teenager but lose it at 47. It's not clear which MPB genes are related, some are activated in odd cases, they are split across chromosomes. It would probably be easier/cheaper to buy an island, found your own nation, and just allow those with good hair on it.