typedef struct {
    int * ID;//the id of user
    char fname[10];//the first name of user
    char lname[10];//the last name of user
    int * score;//the score of user

} users;

users * newuser(int *ID, char fname[], char lname[], int *score) {

    char ne;
    if (ID < 0 || !lname || !fname) return NULL;
    int numID = 100;

    users * U = (users *) malloc(sizeof (users));


    U->ID = (int *) ID;
    strcpy(U->fname, fname);
    strcpy(U->lname, lname);
    U->score = (int *) score;


    int i;

    fflush(stdout);
    printf("Are you new or old user ? n if you are: new press N, old press O  :n ");
    fflush(stdout);
    scanf(" %c ", &ne);




    if (ne == 'N') {
        fflush(stdout);
        printf("choose your ID, between 1 and 1000: n");
        fflush(stdout);
        scanf("%d", &ID);
        U->ID = (int *) malloc(sizeof (int));

        FILE *fp;
        fp = fopen("users.txt", "a");


        fprintf(fp, "%d", ID);

        fprintf(fp, "n");
        fclose(fp);





    }
    if (ne == 'O') {
        fflush(stdout);
        printf("Enter your ID: n");
        fflush(stdout);
        scanf("%d", &ID);
        U->ID = (int *) malloc(sizeof (int));

        FILE *fp;

        fp = fopen("users.txt", "a");


        fprintf(fp, "%d", ID);

        fprintf(fp, "n");
        fclose(fp);



    }


    fflush(stdout);
    printf("Enter your first name: ");
    fflush(stdout);
    scanf(" %s ", fname);
    fname = (char *) malloc(10 * sizeof (char));

    FILE *fp;

    fp = fopen("users.txt", "a");

    gets(fname);
    fprintf(fp, "%s", fname);

    fprintf(fp, "n");
    fclose(fp);

    fflush(stdout);
    printf("Enter your last name:  ");
    fflush(stdout);
    scanf(" %s ", lname);
    lname = (char *) malloc(10 * sizeof (char));










}