MNIST data store in a folder

I am trying to store the images of MNIST training images into a folder. But first, i want to store the images with labels 0 in a serial order, then images with labels 1 in a serial order, so on. Could anyone please guide me how to proceed.

% ========================================================================
%Read and display the MNIST train images and the labels
% ========================================================================
function storemnist
close all;
clear all;

% Loading the training images and the labels
images = loadMNISTImages('train-images.idx3-ubyte');
labels = loadMNISTLabels('train-labels.idx1-ubyte');
image_size = sqrt(size( images, 1));
imageCell={};
Training='TRAINING';
mkdir(Training);
for i =1:length(labels);
%     display(['sample no: ', int2str( i) ,' has label = ',int2str(labels(i) )]);
    img_matrix = reshape( images(:, i), [ image_size ,image_size ]);
    img_matrix = floor( img_matrix *255);
    img_matrix =uint8(img_matrix);

      p=labels(i,:);

          baseFileName = sprintf('%d%d.pgm',p,i); % e.g. "1.png"
          fullFileName = fullfile(Training, baseFileName); 
          imwrite(img_matrix, fullFileName);

end

img_matrix;
end

[HIRAKJYOTI BASUMATARY]

Sorry , i was able to tackle it finally. Sorry for the inconvenience.

[chakradhar Reddy Vardhireddy]

Could you please explain how you figured out it and also please provie assistance of how to load "images = loadMNISTImages('train-images.idx3-ubyte');". I am not able to figure out this. Please let me know about it. Thanks