int List::backup()    {
    FILE *fp;

    if( (fp = fopen(FILE_NAME, "wb") ) == NULL )
        return 1;

    int i;
    Node *dummy;

    fwrite(&members, sizeof(members), 1, fp);
    for(i = 0, dummy = list; i < members; i++, dummy = dummy->next)
        fwrite(dummy, sizeof(Node), 1, fp);

    fclose(fp);
    return 0;
}

int List::load()   {
    FILE *fp;

    if( (fp = fopen(FILE_NAME, "rb")) == NULL )
        return 1;

    int i;
    Node *dummy;

    fread(&members, sizeof(members), 1, fp);
    list = dummy;

    for(i = 0; i < members; i++, dummy = dummy->next)   {
        dummy = new Node;
        fread(dummy, sizeof(Node), 1, fp);
    }

    return 0;
}