def preprocess_line(line, mid):
    """
    Preprocesses a line and infers the text that belongs to the first and second 
    columns.
    
    Args
    
    line (string): A line from the exam
    mid (int): Index where the second column is considered to start
    
    """
    
    if len(line) <= mid+4:
        col1 = line[0:mid+4].strip()
        col2 = ""
    else:
        col1 = line[0:mid+4].strip() if line[0:mid+4] != " "*(mid+4) else ""
        col2 = line[mid+4:].strip()
    return col1, col2