Convert the copied picture to any layer in your own layer. If you don't convert to your own layers, you can't delete those layers, because those pictures are drawn by those layers. For example, you used to have only 0 floors. After you select all the pasted pictures and convert them into 0 layers, you can delete the layers you made. When deleting, select the layer to be deleted in the upper right corner of Format-Layer, and "Delete" will appear. A little wordy, I hope I can help you!