How to work with lists in prolog?

Question

Prolog

Guys who worked with the prologue? Show me how it works.
There is such a task:
* In the list of characters S1, S2, ..., Sn find all occurrences of the specified word, if the separator between words is one or more spaces.
Found this code somewhere

count(X,X,1):-!. 
count(_,Y,0):-atomic(Y),!. 
count(X,Y,N):- 
        Y=..[_|Subs], 
        count_list(X,Subs,N).        
count_list(_,[],0):-!. 
count_list(X,[H|T],N):- 
        count(X,H,N1), 
        count_list(X,T,N2), 
        N is N1+N2. 

start:-readln(S),read(Sl),count_list(Sl,S,N),write('N = '),write(N).

So, how can you run it? What to write on the query panel?