Importing IP List from file

Anybody wants to give a go at this below ?
So basically these TLD’s come from the onsite website in this form for IPv4 and IPv6
Let’s start simple and only look at IPv4

/log info “Loading GR ipv4 address list”
/ip firewall address-list remove [/ip firewall address-list find list=GR]
/ip firewall address-list
:do { add address=2.84.0.0/14 list=GR } on-error={}
:do { add address=5.54.0.0/15 list=GR } on-error={}
:do { add address=5.144.192.0/18 list=GR } on-error={}
:do { add address=5.172.192.0/20 list=GR } on-error={}
:do { add address=5.203.0.0/16 list=GR } on-error={}
:do { add address=31.14.168.0/21 list=GR } on-error={}

I don’t have the impression that the logic below handles it well. It should throw away/ignore anything besides X.X.X.X/Y and then import it into a ACL.
Regex guru’s here ?

:while ([:len $data]!=0) do={
:if ([:pick $data 0 [:find $data “\n”]]~“^([0-2]{0,1}[0-9]{1,2}\.){3}[0-2]{0,1}[0-9]{1,2}(\/[0-3]{0,1}[0-9]{1,1}){0,1}”) do={
:do {add list=$blacklist address=([:pick $data 0 [:find $data $delimiter]].$cidr) } on-error={}