I have 32 bed files and I hope to generate a unique annotation file from them by merging the features that shows overlapping regions from more than one individual files. For instance, if I got region coordinates: 1-15 and 13-17, the output should be 1-17. Any features only appearing in one sample will be discarded. Is there any tools I could use? I searched bedtools but there seem to be no suitable tools for this task.