code: def readBIM(fileName):
      
      # Reading the first BIM file
      snps = set()
      with open(fileName, "r") as inputFile:
          for line in inputFile:
              row = line.rstrip("\r\n").split("\t")
              snpName = row[1]
              snps.add(snpName)
  
      return snps
docs: Reads a BIM file.
  
      :param fileName: the name of the BIM file to read.
  
      :type fileName: str
  
      :returns: the set of markers in the BIM file.
  
      Reads a Plink BIM file and extract the name of the markers. There is one
      marker per line, and the name of the marker is in the second column. There
      is no header in the BIM file.