fprintf showing multiple boxes instead of value

Hi i was trying to display student id: 164335 as im working on digit recognition using CNN

but instead it shows multiple boxes and not 164335

and when i change the script label = classify ( net, I) to label(k) = classify ( net , I ) with added script k = k + 1 the net recognize the digit wrongly

Below is the script

myFolder = 'D:\CNN test\segmentedImages1';
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.png'); 
theFiles = dir(filePattern);
storedStructure = load('test2.mat');
net = storedStructure.net;
%i = 0;
label = zeros(1,1e6);
%label = [];
for k = 2 : length(theFiles)
    baseFileName = theFiles(k).name;
    fullFileName = fullfile(theFiles(k).folder, baseFileName);
    fprintf(1, 'Now reading %s\n', fullFileName);
    I = imread(fullFileName);
    subplot(3, 4, k);
    imshow(I);  % Display image.
    drawnow; % Force display to update immediately.
    %label(k) = classify(net,I);
    %i = 0;
    k = k + 1;
    label(k)=(classify(net,I));
    title([' Recognized Digit is ' char(label(k))])
end
%% Displaying Detected Text
fprintf( 'student id: %s\n',label)