while(<DATA>) {
    chomp;
    $erg =  b262b10($_); # scalar context is important!
    print $erg, "\n";
}
# equivalent to 
# sub b262b10{()=a..lc pop}
# but with explaining output
sub b262b10{@_=a..lc pop; print join " ", @_, "\n";@_}
__DATA__
A
Z
AA
AZ
BA
ZZ
AAA
ZBA
__END__
# without the debug-output:
1
26
27
52
53
702
703
17629
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