def capitalise_string(string):
    """
    Capitalise the first letter of each word in a string. The original string may contain ().
    """
    capitalised_string = ''
    string_list = string.lower().split(' ')
    for i in range(len(string_list)):
        if not string_list[i]:
            continue
        elif string_list[i][0] != '(':
            capitalised_string += string_list[i].capitalize() + ' '
        else:
            capitalised_string += '(' + string_list[i][1:].capitalize() + ' '

    return capitalised_string[:-1]