use warnings;
use strict;

my $SPACER = "\n\n";

while (my $line = <DATA>) {
    $line =~ s|^\s+||;  ## trim leading whitespace
    $line =~ s|\s+$||;  ## trim trailing whitespace
    $line =~ s|([.?!]+)\s*|$1$SPACER|g;       ## break at [.?!]
    $line =~ s|([a-z])([A-Z])|$1$SPACER$2|g;  ## break at camelCase
    print $line . $SPACER;
}