Thanks

very clear and nice use of uppercase.

really fast to understand

set(a + b) может быть чуть быстрее для небольших списков, так как:
a + b создаёт новый список за линейное время (O(n + m)), но без накладных расходов на вызов методов.
set(a).union(b) требует создания промежуточного множества и вызова метода, что добавляет небольшую константу.

elegant solution

Nice code!

ok so what? it behaves the same way as a function does.

are we deadass

Thats a pretty nice compact solution, ty!

it's never a good option to put the same name in 2 things (the function and the var are the same)

somebody wasted ten thousand lines using brute force to solve a kata but you used 5

Oh man that's clever. I'm just learning Python and I had no idea int() could be used that way.

oops, it's retired - try again! 😉

suggestions:

• make the target amount of unique phone numbers variable (not constant 10 billion)
• don't provide an input list, just the alphabet size (as suggested below)