def read_bst_file(filename):
    """Reads data from sequence alignment test file.
    
    Args:
        filename (str): The file containing the edge list.
      
    Returns:
        list: The frequencies for each key.
    """
    with open(filename, 'r') as f:
        next(f) # Skip first line
        freq = [int(x) for x in next(f).strip().split(',')]
        return freq