import os
import shutil

def merge_images(input_folder, output_folder):
    if not os.path.exists(output_folder):
        os.mkdir(output_folder)

    count = 0
    for root, _, filenames in os.walk(input_folder):
        for fn in filenames:
            if fn.endswith('.jpg'):
                count += 1
                shutil.copy(os.path.join(root, fn), os.path.join(output_folder, 'c_{:010d}.jpg'.format(count)))

if __name__ == '__main__':
    merge_images('p', 'output')