I need to make a long code that already has loops loop.

%I need everything inside the loop (for=k1:L ) to loop L amount of times.
%Each loop should create a new startingpos and do new calculations but it
%does not. The answer (Finalprob) should be an average of all of the loops
%that find probability. It should be average probability, however right now
%it just reprints one value of (probu).
L=10000
for k=1:L
prime=primes(250); %prime numbers less than 250
 Prob_prime=0.85; %setup for prime probability
 Prob_other=0.3;
startingpos=randi(250,1,1) %makes a random number for position between 0-250. START
position=startingpos;
for f=2:15 %for loop for all moves after the first position.
    r=randi(2,1,1);
if (position(f-1)==1) %makes sure that it cannot go to 0
    position(f)=2;
elseif (position(f-1)==250) %makes sure it cant go over 250
    position(f)=249;
elseif (r==1) %makes a 50% chance that it counts up or down.
    position(f)=position(f-1)+1; 
else
    position(f)=position(f-1)-1;
    
    x1=Prob_prime*position(f-1);
 x2=Prob_other*position(f-1);
d1=position(f-1)-x1;
d2=position(f-1)-x2;

end
end
disp('Position = ');
disp(position);
%plot(1:length(position),position)
%xlabel('time')
%ylabel('Position')
probability=abs(startingpos-position(length(position)))/15*100
%%
count=0
TF=isprime(position);
B=nnz(TF(1,:)==1);
if numel(B)>=4 && numel(B)<=9
    count=count+1;
end
probu=sum(probability);
FinalProb=probu/L;
end
disp(FinalProb)