select a random block out of a list

[n00ne]

hi everyone, so basically i'm trying to make a skript that places "random" blocks in a specific area but i want to use only some specific blocks, what would be the most efficient way to randomly select a block out from a list of blocks that i want to use?

 

[TheLeviDR]

command /random:
trigger:
add grass block to {_random::*}
add stone to {_random::*}
set {_block} to random element of {_random::*}

I hope it can help.