# Pastebin OtfP4k2A
sub add(Int $a, Int $b) {$a + $b} 
sub con(Str $a, Str $b) {$a ~ $b} 

my IntStr $a = <1>;
my IntStr $b = <2>;

say add $a, $b;    #3
say con $a, $b;    #12