I have .sam files generated by bbmap. I was mapping paired reads to a set of scaffolds that have non-standard names (I have these names, they are a bundle of assembly generated names and spike-in names). Now I need to extract the number of reads that were mapped to each of the scaffolds. BBmap gives me only coverage information per scaffold. But I also want to try working with a number of reads mapped to each scaffold. How can I extract this information?