42.034 41.630 40.158 26.823 26.366 25.289 23.949

34.712 35.133 35.185 35.577 28.463 28.412 30.831

33.490 33.839 32.059 32.072 33.425 33.349 34.709
<\code>

the groups are always of equal length and can be arranged in more than one line long, (if the group is large, say 500 numbers long); seperated by blank lines ! 
My question is: how should I subtract the first element of array 2 from array 1, array 3 from array 2, similarly for the second element and so on till the end of the group?


i.e.:

34.712-42.034,35.133-41.630,35.185-40.158 ...till the end of each group


33.490-34.712,33.839-35.133   ..................


I did use pairwise ,
use List::MoreUtils qw<pairwise>;
But i am unable to assign them into array correctly

<code>

while (<IN>){

my @list1 = split ' ', <IN>;

my @list2 = split ' ', <IN>;

my @diff  = pairwise { $b - $a } @list2, @list1;

}