# Modification: our (%by_count, %by_word);
$ time perl choroba_mod.pl big1.txt big2.txt big3.txt >oo1.txt
start
get properties: 9 secs
sort + output: 14 secs
total: 23 secs

real  0m 23.083s
user  0m 22.568s
sys   0m  0.491s

# Run parallel on physical cores: max_workers => 4
$ time taskset -c 0-31 perl mce.pl big1.txt big2.txt big3.txt >oo2.txt
start
get properties + pre-sort: 14 secs
final sort + output: 2 secs
total: 16 secs

real  0m 15.434s
user  0m 52.223s
sys   0m  0.824s

# Verify correctness:
$ diff cpp.tmp oo1.txt  # choroba
$ diff cpp.tmp oo2.txt  # MCE  4 workers