How do you make a matrix with alternating numbers in a nested loop?

I am trying to make an alternating 5x5 matrixs of 2s and 3s, starting with 2 on the top left corner, in a nested loop. My professor recommended using rem() or mod() functions to make the pattern, but I'm not really sure how to do that. I have been able to get every other column to have alternating numbers, but not all of them and not with the correct numbers. This is my code so far.

Y=ones(5);

for i = 1:2:(length(Y))
    for j = 1:2:(length(Y))
        Y(i,j) = mod(i,2).*2
    end  
end
      

Answer 1

[Voss]

N = 5;
% start with a matrix of all 3's
% (then the code will place 2's at the appropriate places)
Y = 3*ones(N);
% loop over all rows (in general, every row gets 
% a 2 somewhere, not just the odd rows):
for i = 1:N
    % determine which column the first 2 goes in:
    % odd i: start in column 1 (e.g., row 1 has a 2 in column 1)
    % even i: start in column 2 (e.g., row 2 has a 2 in column 2)
    start_column = 2-mod(i,2);
    % place 2's in each alternate column of row i, starting with
    % start_column:
    for j = start_column:2:N
        Y(i,j) = 2;
    end  
end
disp(Y);

     2     3     2     3     2
     3     2     3     2     3
     2     3     2     3     2
     3     2     3     2     3
     2     3     2     3     2

Answer 2

[Torsten]

 n = 5;
 x = zeros(n^2,1);
 x(1:2:end) = 2;
 x(2:2:end-1) = 3;
 x = reshape(x,n,n)