Martin Brown book page 33

mnooning has asked for the wisdom of the Perl Monks concerning the following question:

Hello.
I am reading DeBUGGING PERL by Martin Brown. Page 33
shows

    sub first {print 'First' }
    sub second {print 'Second' }
    print(2,3,first,second);
[download]

The result is

FirstSecond231

which I have checked. It really is. So where does that
last digit '1' come from? Why isn't it just

'FirstSecond23'