%
%
%  Input: integer positive (natural) n.
%  Output: the highest prime number p such that p<n.
%
%
n=input('Give the natural number n :');

p=-1;
ind=0;
for(i=1:1:(n-1))
   ind=0;
   for(j=2:1:n/2)
      if(rem(i,j)==0) %divides
         ind=1;
         break;
      end   
   end   
   if(ind==0)
      p=i;
   end
   
end

disp(['p (p<n) is:' num2str(p)]);