gistfile1.txt

#!/usr/bin/env perl6

sub x([$first, *@rest], &op) {
    my $*I = 0;
    for @rest.kv -> $*I, $r { op($first, $r); }
}

my %M;
x("blosum.dat".IO.lines, sub ($h,$l) { 
    my @h = $h.words;
    x($l.words, sub ($k, $v) { 
        %M{$k}{@h[$*I]} = $v;
    });
});
 
say %M<A><Q>;