use strict;

#-- Change the end of record character to read the whole file.
undef $/;

#-- Create the array
my @ary = split (/\s+/,<DATA>);
print join(" / ", @ary);

__DATA__
boop noop boop crep
a1 a2 a3 a4 a5
b1 b2
c1 c2 c3 c4

d1 d2 d3