def copy_to_len_sliced(s, l):
    """Returns the maximim length string made of copies of `s` with the length 
    exactly `l`; if the length of `s` doesn't match, it ends with the beginning
    slice of `s`.
    
    Parameters
    ----------
    s : string
        String to be copied and sliced.
    l : int
        The length of `output`.
        
    Returns
    -------
    output : string
        Copies of `s` stuck together until their length is `l`.
    """
    
    # Initialisations
    s_list = [ ]
    output_list = [ ]
    
    for i in range(len(s)):
        s_list.append(s[i])
        
    while len(output_list) < l - len(s_list):
        output_list += s_list
        
    output_list += s_list[:l-len(output_list)]
    output = "".join(output_list)

    return output