use strict;
use warnings;

my %word_counts;
while (<>) {
   for (split(' ', $_)) {
      s/[,.!?:;"'<>]//g; 
      ++$word_counts{lc($_)};
   }
}

for my $word (sort keys(%word_counts)) {
   print "$word occurred $word_counts{$word} times\n";
}