sub hash_style2 {
    my %values;
    my @temp = @master;
    push @{$values{substr($_,0,1)}}, substr($_,2)
        for @temp;
    print "@{$values{a}} <==> @{$values{b}}\n" if $testing;
}

sub ikegami {
    my @temp = @master;
    local $_ = "@temp";
    my @a = /\ba_(\d+)\b/g;
    my @b = /\bb_(\d+)\b/g;
    print "@a <==> @b\n" if $testing;
}