c:\@Work\Perl\monks>perl -wMstrict -le
"my @ra = qw(12 -3 4 71 5 -11 -0.99999 -598 -100203 0.99999 4);
 ;;
 my ($i_lnn) =
   map unpack('x[N] N', $_),
   sort
   map { $ra[$_] >= 0 && $ra[$_] == int($ra[$_]) ? pack('N N', $ra[$_], $_) : () }
   0 .. $#ra
   ;
 ;;
 if (defined $i_lnn) {
   print qq{\$ra[$i_lnn] == lowest natural number $ra[$i_lnn]};
   }
 else {
   print 'no lowest natural number in array';
   }
"
$ra[2] == lowest natural number 4