Update: 122 Just realized that there is no requirement to output to STDOUT, so output to STDERR instead and knock off another character.

#234567890123456789012345678901234567890123456789012345678901234567890
+1234567890123456789012345678901234567890123456789012
@u="0335443554366887798866555766"=~/./g;$_+=<>;warn"$_ is ",$_=$_-4?$_
+<20?$u[$_]||4:$u[chop]+$u[$_+18]:magic,".\n"until/a/

[download]

Update: 123

#234567890123456789012345678901234567890123456789012345678901234567890
+12345678901234567890123456789012345678901234567890123
@u='0335443554366887798866555766'=~/./g;$_+=<>;print"$_ is ",$_=$_-4?$
+_<20?$u[$_]||4:$u[chop]+$u[$_+18]:magic,".\n"until/a/

[download]

121 124 strokes

Update 2 Whoops. Broken for zero. Add three strokes.

#    12345678901234567890123456789012345678901234567890123456789012345
+67890123456789012345678901234567890123456789012345678901234
perl -E'@u="0335443554366887798866555766"=~/./g;$_+=<>;say"$_ is ",$_=
+$_-4?$_<20?$u[$_]||4:$u[chop]+$u[18+$_]:magic,"."while/\d/'

[download]

or alternately, also 124 strokes:

#234567890123456789012345678901234567890123456789012345678901234567890
+123456789012345678901234567890123456789012345678901234
@u='0335443554366887798866555766'=~/./g;$_=pop;print"$_ is ",$_=$_-4?$
+_<20?$u[$_]||4:$u[chop]+$u[$_+18]:magic,".\n"until/\D/

[download]

Updated: Argh. posted wrong (broken) version. Try again.

#    12345678901234567890123456789012345678901234567890123456789012345
+67890123456789012345678901234567890123456789012345678901
perl -E'@u="0335443554366887798866555766"=~/./g;$_+=<>;say"$_ is ",$_=
+$_-4?$_<20?$u[$_]:$u[chop]+$u[18+$_]:magic,"."while/\d/'

[download]

or alternately, also 121 strokes:

#234567890123456789012345678901234567890123456789012345678901234567890
+123456789012345678901234567890123456789012345678901
@u='0335443554366887798866555766'=~/./g;$_=pop;print"$_ is ",$_=$_-4?$
+_<20?$u[$_]:$u[chop]+$u[$_+18]:magic,".\n"until/\D/

[download]

In reply to Re: Code Golf: Four is magic by thundergnat
in thread Code Golf: Four is magic by deMize

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