use strict;
use warnings;
my @labels = ('fee', 'fi', 'fo', 'fum');
open(my $fh, '<', "folks.txt") || die "can't open folks: $!";
my @list;
while (<$fh>) {
  chomp;
  push @list, [split /,/];
}

for my $element (@list) {
  print "$labels[0],$element->[0],$element->[1]\n";
}
for my $element (@list) {
  print "$labels[1],$element->[0],$element->[2]\n";
}
for my $element (@list) {
  print "$labels[2],$element->[0],$element->[3]\n";
}
for my $element (@list) {
  print "$labels[3],$element->[0],$element->[4]\n";
}