admin@kzr-home:~$ cp gibberish.txt{,.bak}
admin@kzr-home:~$ for i in {1..5000}; do cat gibberish.txt.bak >> gibberish.txt; done
admin@kzr-home:~$ time ./task.py 

    1. people
    2. sound water would water people or many from would than each sound of people who what see number was up at has there the from be is their can at who some was their water day with word have call had I said them with and you
    3. 550079
    4. 550097
    5. 3
    

real	0m19.991s
user	0m19.824s
sys	0m0.164s

admin@kzr-home:~$ time ./task_fast.py 

    1. people
    2. sound water would water people or many from would than each sound of people who what see number was up at has there the from be is their can at who some was their water day with word have call had I said them with and you
    3. 28
    4. 97
    5. 3
    

real	0m14.403s
user	0m13.952s
sys	0m0.448s