function A=LU_naive(A)
[m,n]=size(A);
A = sym(A);
disp('Begin');
for k=1:min(m, n)-1
    for i=k+1:m
        p = sym(-A(i,k)/A(k,k));
        display(['L' num2str(i) '<- L' num2str(i) ' + (' char(p) ')*L' num2str(k)]);
        for j=k:n
           A(i, j) = A(i, j) + p*A(k, j); % Be careful: the "-" sign is built in the definition of p
        end
        disp(A)
        answer = input('Continue? (y/n) ', 's');
        if (answer == 'n')
           break;
        end   
    end
end    
disp('End');