Move contents of subfolders up one level (hundreds of parent folders, all subfolder have the same name)

Move contents of subfolders up one level (hundreds of parent folders, all subfolder have the same name)

Is there a built-in way (WIN7) or third-party utility I can use that will allow me to move the contents of the subfolders of my hundreds of parent folders up one level?
To illustrate:
PARENT1/gallery/filex.jpg
PARENT1/gallery/filey.jpg
PARENT1/gallery/filez.jpg
PARENT2/gallery/filex.jpg
PARENT2/gallery/filey.jpg
PARENT2/gallery/filez.jpg
What I want to do (at a single batch action, not individual per folder) is:
PARENT1/filex.jpg
PARENT1/filey.jpg
PARENT1/filez.jpg
PARENT2/filex.jpg
PARENT2/filey.jpg
PARENT2/filez.jpg
Parents have varying names, but all subfolders have the same name "gallery". Is there any quick and painless way to do this? I have roughly 650+ PARENT folders.