code: def filter_paired(list):
  	
  	pairs = {}
  	filtered = []
  	for id in list:
  		read = id.rsplit('/')[0]
  		if read not in pairs:
  			pairs[read] = []
  		pairs[read].append(id)
  	for read in pairs:
  		ids = pairs[read]
  		if len(ids) == 2:
  			filtered.extend(ids)
  	return set(filtered)
docs: require that both pairs are mapped in the sam file in order to remove the reads