use strict;
use warnings;
use feature 'say';
use List::Util 'max';

my %count;

local $/ = "arn:aws:iam::";

while (my $line = <DATA>) {
    chomp $line;
    $line =~ s!$/!! if $. == 1;
    next if $line eq '';

    my ($key, @values) = split(/\n/, $line);
    $count{$key} = scalar @values;
}

my @keys = keys %count;
my $longest = max map { length } @keys;

for my $key (sort @keys) {
    say sprintf("%-${longest}s : %3d", $key, $count{$key});
}
__DATA__
arn:aws:iam::11111111111:role/ADFS-MyRoleName
"Alexa for Business"
"AWS Certificate Manager"
"AWS Certificate Manager Private Certificate Authority"
"AWS Amplify"
"Manage - Amazon API Gateway"
"AWS App Mesh"
"Amazon AppStream 2.0"
"AWS AppSync"
"Amazon Athena"
"AWS Auto Scaling"

arn:aws:iam::12345678901:role/Role2-Role2
"Alexa for Business"
"AWS Certificate Manager"
"AWS Certificate Manager Private Certificate Authority"
"AWS Amplify"
"Manage - Amazon API Gateway"
"Application Auto Scaling"
"AWS App Mesh"
"Amazon AppStream 2.0"
"AWS AppSync"