or download this
pp \$a;;
[Malformed UTF-8 character (fatal) at C:/Perl64/lib/Data/Dump.pm line
+458, <STDIN> line 13.
...
Malformed UTF-8 character (unexpected continuation byte 0x80, with no
+preceding start byte) in unpack
Malformed UTF-8 character (unexpected continuation byte 0x80, with no
+preceding start byte) in unpack
4100000000000000